Turkish Labour Law In 2025 (1): Five (+1) Constitutional Court Decisions On Employment Relationships

INTRODUCTION

In 2025, as in the past several years, the decisions of the Constitutional Court have ranked among the most intensely debated issues on the agenda of Turkish labour law. The rulings delivered by the Court have not merely resolved specific disputes, but have also brought issues such as employment security, union rights, and labour litigation into focus by scrutinizing their constitutional foundations. Below, five decisions arising from individual applications, together with one decision rendered in the context of a concrete norm review are examined. These rulings stand out due to their potential impact on the future development of Turkish labour relations.

The constitutional review jurisprudence of 2025 is particularly notable in two respects. First, it reflects an increasing awareness of the deepening power and information asymmetry in working life and the need to take this imbalance into account in labour litigation. Second, it demonstrates a sustained sensitivity toward ensuring that constitutionally protected collective rights do not remain merely declaratory but are effectively implemented in practice. In recent years, the Constitutional Court's rights-based approach—one that engages with the historical depth and normative foundations of the institutions governing labour relations—has given fresh momentum to the development of Turkish labour law.

1. FACILITATING THE EMPLOYEE'S BURDEN OF PROOF

Cafer Oruç (2021/3130, 4/2/2025)

Some of the decisions rendered by the Constitutional Court in 2025 relate to labour proceedings and the standards of proof applied therein. These decisions, which are directly connected to employees' rights, are significant in that they remedy the adverse effects of technological and social developments on the right to a fair trial and to prevent rights arising from employment relationships from losing their constitutional significance. In recent years, the increasing volume of data held by employers —such as visual recordings, audio materials, and tracking data— together with the introduction of new data-processing tools, including artificial intelligence systems, has rapidly deepened the information asymmetry between employers and employees.

In addition to this development, as illustrated by the widespread adoption of remote work under the catalytic effect of the pandemic, reduced interpersonal contact among employees and the growing physical and psychological distance between them have made it increasingly difficult for employees to prove working conditions through witness testimony. The diminishing availability of witness evidence —traditionally the most accessible means of proof for employees— undermines employees' efforts to seek legal remedy and poses the risk of their rights losing their meaning. The Constitutional Court in its other decisions¹, although not directly relying on the structural change described above, has revealed its approach to lowering evidentiary thresholds or facilitating proof for employees in order to render the right to legal remedies effective, within the context of the right to a reasoned decision.

Within this context, one of the Constitutional Court's decisions delivered in 2025 that is particularly significant for labour litigation was rendered upon the individual application lodged by the employee Cafer Oruç. The applicant claimed that he had worked as a pre-accounting clerk between 27 September 2014 and 12 January 2018 and that he had effectively terminated his employment contract with just cause due to the non-payment of wages for work performed on national and general holidays and for overtime work, as well as due to the psychological pressure to which he had been subjected. Accordingly, he filed an action claiming severance pay, overtime pay, and national holiday and vacation pay.

The court of first instance partially accepted the claims, awarding severance pay as well as national holiday and vacation pay. It found, on the basis of witness statements and the case file, that the applicant had worked on such days and that the employer had failed to prove payment for these services. However, the court rejected the overtime work claim, holding that the signed payroll records did not include any overtime accrual and that the applicant had failed to prove overtime work (para. 5).

Upon both parties appealing the first-instance decision, the Diyarbakır Regional Appellate Court definitively dismissed the entire action, including the claim for national and public holiday wages, holding that the applicant's allegations were essentially based on statements of a hostile witness, that the connection between the email printouts and the employer had not been proven, and that a conclusion cannot be reached on the basis of a single witness statement unsupported by auxiliary evidence (para. 8). Thereafter, in his individual application, the applicant alleged that no effective examination had been conducted with respect to the emails and the computer records (hard disks and log records) not submitted by the employer, and that excluding the witness solely because he had a lawsuit against the employer was incompatible with the right to a fair trial and the right to a reasoned judgment, thus claiming a violation of the Constitution (para. 10).

In its examination, the Constitutional Court stated that it was not bound by the legal characterization of the applicant's allegations and that the constitutional assessment of the facts and circumstances fell within its competence, and therefore conducted its review under the right to a reasoned decision (p.11). In its examination on the merits, the Constitutional Court emphasized that the right to a fair trial guaranteed under Article 36 of the Constitution includes the right to a reasoned judgment, and that while courts are not required to respond in detail to every allegation, they must address decisive, clear, and concrete claims with relevant and sufficient reasoning. In this context, it was held that the Regional Appellate Court's acceptance of the fact that the applicant's witness had filed a lawsuit against the same employer as an element that rendered the witness evidence worthless, and its failure to discuss any of these statements, was incompatible with the constitutional obligation of reasoning. Likewise, the failure to explain in the decision's reasoning why the technical examinations recommended in the expert report regarding the source of the emails had not been conducted or why such evidence had not been considered sufficient, was identified as a significant deficit (para. 13-17).

As per above reasons, the Constitutional Court concluded that, when the proceedings were assessed as a whole, the applicant's right to a reasoned decision had been violated. It was accepted that a retrial would constitute sufficient redress for the violation, and it was particularly emphasized that the violation decision did not amount to an uphold or dismissal on the merits of the dispute. Accordingly, it was held that the relevant courts should reassess the evidence and render a new decision in line with the principles set out by the Constitutional Court, while the claim for non-pecuniary damages was rejected on the grounds that a retrial would provide sufficient redress.

The decision rendered by the Constitutional Court in the Cafer Oruç application clearly reveals the problems arising from the increasingly deepening information asymmetry between employees and employers, in procedural terms. Today, the employee's work performance, and more broadly the workplace, have become largely traceable through digital infrastructures under the control of the employer (such as email systems, internal networks, log records, access cards, and software records). By contrast, since the employees are neither the direct owner nor the administrator of these data, they face a structural disadvantage in proving claims arising from employment disputes. This situation creates a setting in which the seemingly neutral principle of classical law of evidence as "each party must prove its claims" is capable to produce practically unequal outcomes in modern employment relations.

From this perspective, the emails, computer records, and log data discussed in the Cafer Oruç decision should be regarded not merely as elements of a discussion of concrete evidence, but also as elements shaping the substantive content of the right to a fair trial. Expecting the employee to provide complete and exact proof under classical evidentiary standards, without the submission of digital evidence under the employer's control or without conducting an effective examination thereof, renders the proceedings formally impartial but substantively detrimental to the employee. Indeed, such an approach disregards the employee's limited access to evidence and results in a practical aggravation of the burden of proof, which may lead to a violation of the right to a fair trial in connection with the right to a reasoned decision.

Accordingly, the decision must be read as an important warning that the asymmetrical structure of information and evidence in employment disputes, created by technological phenomena such as digitalization and artificial systems, must be regarded in judicial assessments. In this regard, courts are required not merely to rely on the existing evidence, but to discuss in the light of constitutional guarantees, whether digital records under the employer's control have been submitted, whether their non-submission is based on a reasonable justification, and how this situation affects the balance of proof, in particular. Otherwise, proceedings conducted under unchanging classical rules of evidence, despite the changing working methods in the digital age, would produce results that render the right to legal remedies practically meaningless for employees.

2. SUSPICION TERMINATION AND THE PROTECTION OF PRIVACY:

Erdem Kaplan and Others (2019/34183, 29/4/2025)

The State of Emergency (SoE) declared in Türkiye on 21 July 2016, which was extended seven times at three-month intervals, came to an end on 19 July 2018. Following the SoE period, a large number of legal processes during that time were brought before judicial authorities. The individual application concerning the decision was submitted to the Constitutional Court through the joinder of applications filed by numerous employees whose employment contracts had been terminated during the SoE period. However, it should be noted that the Constitutional Court had previously rendered decisions adopting a similar approach on this matter², therefore, the decision constitutes a continuation of the earlier case-law. Moreover, even after the decision examined by the Constitutional Court in 2025, further judgments have been delivered in the same direction³. The significance of the decision discussed below lies is that, together with other similar decisions rendered in 2025 and earlier, it delineates reasonable limits, with a contemporary legal approach, on how the employee's right to privacy should be protected within the framework of termination of employment contracts in Turkish labour law.

In the case concerning the decision, the applicants' employment contracts were terminated by their employers on the ground that they were reported to be in connection/affiliation with terrorist organizations under Decree-Law No. 667, and accordingly, that the employer-employee trust relationship was damaged (para. 4). The applicants' common characteristic is that, prior to the termination of their employment contracts, they were employed in the public sector or in private companies associated to the public sector, as employees. Following the terminations, actions for reinstatement were filed; some of these actions were upheld at courts of first instance, while others were dismissed. However, appeals against the admission decisions were upheld at the appellate or cassation stages, and ultimately it was concluded that the terminations were based on valid grounds (para. 5).

Some of the applicants were employed by companies owned by municipalities, others by private companies engaged in service procurement relationships with municipalities, and others by administrations or companies vested with public power privileges. In concluding that the terminations were lawful, the courts of first instance and higher courts relied on intelligence information concerning the applicants or their family members, ongoing or concluded criminal investigations and prosecutions, and even conviction judgments rendered long before the date of termination. Despite the existence of acquittals or decisions of non-prosecution in respect of some applicants, the courts assessed these elements as a whole and assumed that the trust relationship had been damaged from the employers' perspective (para. 6).

The applicants subsequently lodged individual applications, alleging that their right to privacy had been violated during the proceedings and, additionally, that their right to a trial within a reasonable time had been breached due to the excessive length of the proceedings. Owing to the existence of a legal connection in terms of subject matter, the Constitutional Court joined the similar applications with individual application no. 2019/34183 (the Erdem Kaplan application) and conducted its examination through that file.

The Constitutional Court first examined the applications in relation to the right to a trial within a reasonable time. In its decision, the Court stated that, pursuant to the amendments introduced by Law No. 7499, applicants are required to apply first to the Compensation Commission in cases alleging a violation of the reasonable-time requirement. Accordingly, individual applications lodged without first applying to the Commission were declared inadmissible for failure to exhaust available remedies (para. 11).

The Court separately assessed the applicants' allegation of a violation of the right to privacy. In its decision, the Court held that, with regard to the process concerning the termination of the employment contract, the right to privacy is not directly applicable; however, taking into account that, in the present case, the interference with professional life had a serious impact on the applicants' privacy and that such impact had reached a certain level of severity, and by referring to its previous decisions⁴ including assessments in the same vein, the application was found to be admissible for examination in the scope of the right to privacy (para. 16).

In its decision, the Constitutional Court first considered Article 15 of the Constitution, which imposes restrictions on the exercise of fundamental rights and freedoms times of war, mobilization, or States of Emergency, given that the legal act in question occurred during the State of Emergency. The Court was of the opinion that the right to privacy does not fall within the category of fundamental rights and freedoms listed under Article 15(2) of the Constitution, which may not be suspended or interfered with in their essence even during exceptional periods such as a state of emergency, war, or mobilization; nevertheless, it emphasized that even under State of Emergency conditions, any interference with fundamental rights and freedoms must not exceed the extent strictly required by the situation, must not be arbitrary, and must be supported by concrete facts (paras. 21–22). In assessing proportionality in the context of this case, the Court found that, with regard to the applicants, intelligence information, ongoing investigations, acquittal judgments, non-prosecution decisions, and very old convictions relied upon as grounds for suspicion termination, had been used without establishing a connection with the nature of the applicants' duties and their personal circumstances; moreover, it was determined that no serious, strong, and objective reasons demonstrating a breakdown of the trust relationship had been revealed in the decision (paras. 27–30). Within the framework of constitutional review, the Constitutional Court concluded that Article 15 of the Constitution regulating the suspension and restriction of the exercise of fundamental rights and freedoms during the State of Emergency, was not applicable to the circumstances of the case (para. 31) and ultimately found that the applicants' right to privacy had been violated (para. 32), ordering a retrial.

As indicated above, the decision is consistent with the Constitutional Court's earlier case-law. The issue of suspicion termination has been examined primarily within the framework of the right to privacy and the proportionality principle governing restrictions on fundamental rights during the State of Emergency period. However, the approach consistently adopted by the Constitutional Court in this respect—also reflected in several decisions delivered in 2025—is of particular importance from the perspective of Turkish labour law. First, as in the other decisions on the subject, the decision has clearly revealed that even during the State of Emergency, the concept of suspicion termination does not grant employers an uncontrolled freedom of termination based on a breach of the duty of loyalty⁵. In the decision, the Constitutional Court rightly states that intelligence information, investigations, proceedings, or very old convictions cannot, in themselves, be deemed sufficient to establish that the trust relationship between employer and employee has collapsed; rather, termination must be justified by serious, strong, and objective facts directly related to the employee's duties.

The decision further demonstrates that, in Turkish labour law, the protection afforded to employees through employment security mechanisms cannot be arbitrarily suspended, even under exceptional circumstances such as a State of Emergency. Moreover, both in the present case and in other Constitutional Court judgments adopting a similar approach, it has been constitutionally clarified that an employer's interference with an employee's privacy through the exercise of the right of termination can be considered lawful only to the extent that it is proportionate. Accordingly, the Turkish labour judiciary should, in future cases involving measures likely to encroach upon employees' privacy—such as suspicion termination—take as their primary reference point the Constitutional Court's interpretation of the proportionality principle.

3. WHITE-COLLARS AND THE UNION RIGHT:

Hülya Şimşek (20/3/2025 - 2022/18821)

Some of the decisions rendered by the Constitutional Court in 2025 in the field of labour law concern collective labour law and relate to the review of collective rights guaranteed under the Constitution. Within this category, one of the decisions with the potential to produce significant long-term consequences—arguably the most prominent among them—is the judgment concerning the right of white-collar employees to benefit from a collective bargaining agreement, which is examined below.

In the case brought before the Constitutional Court, the applicant, Hülya Şimşek, worked as a chief accountant (a white-collar employee) at the relevant workplace between 2000 and 2014 and was a member of the Turkish Mine Workers' Union. Although collective bargaining agreements were regularly concluded between the authorised union and the employer, the applicant was classified as "out-of-scope personnel" on the ground that she was a white-collar employee and was therefore excluded from the scope of those agreements. The applicant maintained that wage increases granted to unionised employees had initially been applied to her as well, but that this practice was discontinued as of 2007, resulting in her complete exclusion from wage increases arising from the collective bargaining agreement (para. 8).

Relying on these allegations, the applicant brought an action before the labour court, claiming wage differences arising from the collective bargaining agreement together with other employment-related receivables. The court of first instance dismissed the action, holding that the applicant was out-of-scope personnel and that, under the settled case-law of the Court of Cassation, differences in wage increases between employees covered by a collective bargaining agreement and out-of-scope employees did not constitute a breach of the principle of equal treatment. On appeal, the decision was set aside, and it was emphasised that it was necessary to examine whether there were comparable out-of-scope employees who had nevertheless benefited from increases under the collective bargaining agreement (para. 10).

Upon retrial, the court of first instance found that the increases provided by the collective bargaining agreement had not been applied to any out-of-scope personnel and again dismissed the action. This judgment was subsequently upheld by the appellate court and became final (paras. 11–12). Thereafter, the applicant lodged an individual application with the Constitutional Court, arguing that her exclusion from the collective bargaining agreement rendered her union right practically meaningless. She asserted that, although she should have benefited from the collective bargaining agreement pursuant to Article 39 of Law No. 6356, she had been prevented from doing so, and that her claims in this respect had been dismissed by the domestic courts. Accordingly, she alleged violations of her right to a fair trial, the principle of equality, and her union right (para. 28).

The Constitutional Court examined the dispute not at the level of "unpaid wages" between the employee and her employer, but within the context of the constitutional union rights and freedoms. In its decision, the Court first stated that in relation to the union right under Article 51 of the Constitution, the State has not only have a negative obligation to refrain from interference by public authorities, but also a positive obligation to protect individuals against interference by third parties (para. 36). According to The Court, in the scope of its said positive obligation, the State is required to operate deterrent mechanisms providing effective judicial protection and enabling compensation (para. 37). Accordingly, the judicial review in the decision, focused not on substituting the domestic courts' legal assessment, but on whether those courts had duly taken into account the guarantees afforded to the applicant under Article 51 of the Constitution⁶.

The Constitutional Court stated that the right to collective bargaining agreements guaranteed under Article 53 of the Constitution, can be exercised only collectively; that this right also encompasses the entitlement to benefit from a collective bargaining agreement, and that a right to collective bargaining agreement which produces no practical effect is incompatible with constitutional protection (para. 39). In this context, the Court of Cassation noted that the distinction between "white-collar" and "blue-collar" employees lacks a normative reason, and warned that an expansive interpretation of the white-collar label carries the risk of depriving certain groups of employees of the constitutionally protected right to collective bargaining agreements⁷. It is further recalled by the Constitutional Court that, under the relevant provisions of Law No. 6356, exclusion from collective bargaining agreement is essentially limited to exceptional cases such as employer representative status or participation in collective bargaining negotiations on behalf of the employer.

The Constitutional Court further held that the right to collective bargaining guaranteed under Article 53 of the Constitution can be exercised only collectively, and that this right necessarily encompasses the entitlement to benefit from a collective bargaining agreement. A right to collective bargaining that produces no practical effect, the Court emphasised, is incompatible with constitutional protection (para. 39). In this context, the Court observed that the distinction between "white-collar" and "blue-collar" employees lacks a normative foundation, and warned that an expansive interpretation of the white-collar label carries the risk of depriving certain groups of employees of their constitutionally protected right to benefit from collective bargaining agreements. The Court further recalled that, under the relevant provisions of Law No. 6356, exclusion from a collective bargaining agreement is essentially limited to exceptional cases, such as where the employee acts as an employer representative or participates in collective bargaining negotiations on behalf of the employer.

In relation to the concrete case, the Constitutional Court found that the reasoning adopted by the domestic courts—approving the applicant's exclusion from the collective bargaining agreement solely on the basis of her white-collar status—failed to examine whether she had acted on behalf of the employer or could genuinely be regarded as an employer representative (para. 42). The Court further held that the first-instance court's reliance solely on the finding that "none of the out-of-scope employees had benefited from the collective bargaining agreement" could not substitute for the constitutional examination required under the union right, and that this approach did not meet the standard of relevant and sufficient reasoning (para. 43). Consequently, the Constitutional Court concluded that the applicant's union right had been violated, ordered a retrial, and awarded non-pecuniary damages in respect of the moral harm that could not be remedied solely through retrial.

The Constitutional Court's decision in Hülya Şimşek not only addresses past deficiencies in Turkish labour law but also offers a forward-looking constitutional perspective. In the early stages of Turkish labour law, intellectual workers—who may broadly be characterised as white-collar employees—were excluded from the protective scope of labour legislation in several respects. Article 1/1 of the 1936 Labour Law No. 3008 defined employees as those who worked physically or both physically and intellectually, but included only those intellectual workers whose physical labour prevailed or was equal to their intellectual labour, thereby excluding other intellectual workers from the scope of the law. Although this provision was later challenged before the Constitutional Court on the ground that it conflicted with constitutional principles of social justice and equality, the Court unanimously held that it was not unconstitutional (Constitutional Court, 21/10/1963, E. 1963/172, K. 1963/244).

White-collar employees were fully brought under the protective umbrella of labour law only with the enactment of Labour Law No. 931 in 1967 and, following its annulment on formal grounds, with Labour Law No. 1475 in 1971. While white-collar employees thus gained protection under individual labour law with a delay of nearly thirty years, they were in practice largely prevented from benefiting from collective bargaining agreements through the widespread use of "out-of-scope personnel" clauses. Against this historical background, the significance of the Hülya Şimşek decision lies in the fact that it imposes a constitutional limitation on the continued exclusion of white-collar employees from collective labour law mechanisms. By subjecting the abstract and categorical use of the out-of-scope personnel practice to constitutional scrutiny, the decision re-establishes the normative link between the union right and the right to benefit from collective bargaining agreements.

A second important consequence of the decision concerns its potential impact on union organisation and collective bargaining coverage. By clearly establishing that white-collar status alone does not constitute a legitimate ground for exclusion from a collective bargaining agreement, the Constitutional Court has affirmed the practical effectiveness of union membership as a constitutional requirement. This approach transforms union membership for white-collar employees from a merely symbolic status into one associated with tangible rights and benefits, thereby reducing their reluctance to join unions. At the same time, from the perspective of trade unions, the decision may facilitate the attainment of statutory authorisation thresholds by increasing membership numbers, particularly in workplaces where white-collar employment predominates. In this respect, the Hülya Şimşek decision constitutes a transformative precedent that goes beyond the redress of an individual rights violation and strengthens inclusiveness while expanding the reach of collective bargaining in Turkish collective labour law.

4. RIGHT TO COLLECTIVE ACTION, TERMINATION AS A LAST RESORT AND THE RIGHT TO A FAIR TRIAL

Ali Ateş and Others (8/1/2025 - 2022/27930)

In recent years, reports on professional life published by international organizations such as the International Labour Organization (ILO) and the OECD, have pointed out that phenomena such as the fragmentation of work into tasks detached from a physical workplace on a global scale, the departure from shared workplaces and stable employment relationships, the introduction of artificial intelligence systems in workplaces, and the resulting weakening of face-to-face interaction have led to an erosion of union rights⁸. Moreover, as also noted above, the increasing surveillance activities of employers in the workplace facilitate unlawful interferences with union freedom⁹. In the face of this landscape, it is clear that States which place fundamental rights and freedoms at the center of their legal systems must approach the issue with greater care in order to ensure the effective exercise of collective rights. In the decision examined in detail below, the Constitutional Court likewise assessed the lawfulness of a collective action carried out by a group of employees at their workplace, with a contemporary approach within the context of union freedom.

The case underlying the decision of 8 January 2025 arose from a series of legal disputes following the confirmation of the United Metalworkers' Union as the authorised union in 2016, after it had achieved the required majority at the workplace where the applicants were employed. After the employer objected to the confirmation of the union's authorisation, the employment contract of E.E.—an employee representative who had played an active role in union activities—was terminated. Subsequently, union-member employees, including the applicants, engaged in short-term and peaceful protests at the workplace, demanding the reinstatement of E.E. At the end of this process, the employment contracts of a total of 56 unionised employees were terminated. The applicants then filed actions for reinstatement and union compensation, alleging that the terminations were based on union-related reasons (para. 8).

The Kocaeli 4th Labour Court, acting as the court of first instance, assessed the events following the union's acquisition of authorisation, the employer's conduct, and the scope of the terminations as a whole, and concluded that the dismissals were union-related. Accordingly, it accepted the actions. In its reasoning, the court held that the employees' protests were peaceful and proportionate and did not amount to an unlawful strike; that individual and concrete work orders had not been duly communicated to the employees; and that no effective warning mechanism had been applied prior to the terminations (para. 10). These judgments were set aside by the İstanbul Regional Appellate Court on the ground of inadequate examination. Following retrial, however, the first-instance court again found that the terminations were union-related on similar grounds and awarded union compensation in favour of the applicants (paras. 11–12).

Upon a further appeal, the case was once again brought before the İstanbul Regional Appellate Court, which this time characterised the employees' four-day work stoppage as an "unlawful strike", found the terminations lawful, and definitively dismissed the actions (para. 13).

After exhausting domestic remedies, the applicants lodged individual applications with the Constitutional Court, alleging that the dismissal of their claims for reinstatement and union compensation violated their union rights, and that the excessive length of the proceedings infringed their right to a trial within a reasonable time.

The Constitutional Court first examined the allegation concerning the right to a trial within a reasonable time, in light of the subsidiary nature of individual applications. Referring to the amendments introduced to Law No. 6384, the Court emphasised that, with respect to reasonable-time complaints relating to proceedings pending as of 9 March 2023, exhaustion of the remedy before the Compensation Commission is mandatory. As this remedy had not been exhausted in the present case, the complaint was declared inadmissible for failure to exhaust domestic remedies (para. 20).

With regard to the union right, the Constitutional Court stated that Article 51 of the Constitution imposes not only a negative obligation on the State to refrain from interference, but also positive obligations to ensure effective protection against interferences by third parties, such as employers. In this context, the Court emphasised that the establishment of deterrent legal mechanisms to prevent the obstruction of union activities, and the obligation of judicial authorities to resolve disputes with relevant and sufficient reasoning in line with constitutional interpretation, constitute constitutional requirements (paras. 28–29).

In the concrete case, the Constitutional Court found that, after the union had acquired the authority to conclude a collective bargaining agreement, the employer opposed the confirmation of authorisation and thereby suspended the process, and that, following the dismissal of a leading union activist, employees engaged in short-term and peaceful protests (paras. 36–39). The Court held that such actions must be assessed within the scope of the union right. It further found that the domestic courts' characterisation of the protests as an "unlawful strike" had been made without concretely and convincingly demonstrating factors such as the damage allegedly suffered by the employer, the extent of any loss of production, or the inevitability of termination (para. 43). In particular, the failure to adequately address the principle that termination should be a measure of last resort revealed that the judicial assessment did not meet constitutional standards of protection (para. 44).

For these reasons, the Constitutional Court concluded that, in relation to the allegedly union-related terminations, the judicial authorities had failed to strike a fair balance between the interests of the parties and that the State had not fulfilled its positive obligations with respect to the protection of the union right. Accordingly, it held that Article 51 of the Constitution had been violated (paras. 46–47). The Court ordered a retrial to eliminate the consequences of the violation and awarded non-pecuniary compensation to be paid separately to the applicants in respect of moral harm that could not be remedied solely through retrial, while dismissing the claims for pecuniary compensation.

Primarily, the decision of the Constitutional Court, once again draws a constitutional boundary against the automatic characterization of short-term and peaceful work stoppages executed in the context of union activities as an "unlawful strike"¹⁰. Another key point emphasized in the decision is the obligation of courts, during the judicial phase, to comply with the principles of proportionality and concrete reasoning. In this context, the decision requires the clear demonstration why lenient measures that can enable the continuation of the employment relationship were insufficient before termination, and the scrutiny of the true inevitability of termination. At the same time, the decision reveals that courts, in union disputes, must assess the parties' interests on the basis of concrete facts rather than abstract assumptions, and must particularly refrain from interpretations that unduly restrict constitutional rights.

From the perspective of Turkish labour law, the decision reflects the Constitutional Court's consistent and principled approach to ensuring the effective and deterrent protection of union rights. Indeed, the Court adopted a similar line of reasoning in another judgment delivered in 2025, namely Merve Dabanlı and Others (2022/82213, 15/1/2025).

5. THE EFFECT OF SHAM ON BENEFITING FROM A COLLECTIVE BARGAINING AGREEMENT

Murat Tokar (15/5/2025 - 2022/44255)

In addition to labour law issues that arise in similar forms across different legal systems on a global scale and must therefore be addressed from a universal perspective grounded in fundamental rights and freedoms, disputes concerning the interpretation of regulations specific to Turkish law in conformity with the Constitution may also come before the Constitutional Court. A typical example of this latter category in 2025 is the Constitutional Court's decision of 15 May 2025, which is examined below.

The question of whether employees who, due to sham subcontracting arrangements, are deemed to be employees of the principal employer may benefit from the principal employer's collective bargaining agreement—an issue stemming from the distinctive subcontracting regime of Turkish labour law and one that frequently gives rise to disputes in practice—has also been reflected in the Constitutional Court's case law in 2025. In this context, both the Murat Tokar application and the Veysel Kızıl and Others application (16/9/2025 – 2022/54205) examine, from a constitutional perspective, the right to benefit from a collective bargaining agreement of employees working under an unlawful subcontracting relationship.

In the dispute underlying the Murat Tokar application, the applicant, who in fact worked in the principal activity of the Turkish Coal Enterprises Institution, had for many years been formally employed by a subcontractor. Although this relationship was ultimately characterised as sham by the judicial authorities, the applicant was not permitted to benefit from the collective bargaining agreement to which the authorised union and the principal employer were parties. The dispute concerning the applicant's entitlement to benefit from the collective bargaining agreement centred on whether, following a finding of sham under Article 2 of Labour Law No. 4857—according to which the employee must be regarded as an employee of the principal employer from the outset—the requirements of notifying union membership or paying a solidarity due, as set out in Article 39 of Law No. 6356, could still be imposed.

During the judicial proceedings, both the court of first instance and the regional appellate court concluded that the applicant was entitled to benefit from the collective bargaining agreement as a consequence of the finding of sham. However, the Court of Cassation, relying on its settled case-law, held that the requirement of notifying union membership to the principal employer had to be fulfilled independently and dismissed the claim on this ground (paras. 9–12). The applicant then lodged an individual application, alleging violations of his right to a fair trial, the principle of equality, and his union right.

Before the Constitutional Court, the case raised broader questions concerning the impact of sham subcontracting on union rights, the extent to which the enjoyment of collective rights may be conditioned on formal requirements, and whether such requirements undermine the effective protection of the union right in Turkish labour law. In this respect, the dispute required a joint constitutional assessment of subcontracting practices, union organisation, and the collective bargaining system.

The Constitutional Court examined the dispute in the light of the union right under Article 51 of the Constitution and the right to collective bargaining guaranteed under Article 53 (para. 25). In its decision, the Court first emphasised that the union right is not confined to the State's negative obligation to refrain from interference, but also entails a positive obligation to ensure effective legal protection against interferences by employers. Accordingly, the Court stressed that judicial authorities are required to interpret and apply legal rules in conformity with the Constitution, to strike a fair balance between competing interests, and to provide relevant and sufficient reasoning, particularly in disputes concerning union rights (paras. 29–31).

In the concrete case, the Constitutional Court found that, in light of the finding of sham and the rule under Article 2 of Law No. 4857 requiring the applicant to be regarded as an employee of the principal employer from the outset, the domestic courts had failed to convincingly explain why notification of union membership to the principal employer—who was itself a party to the sham arrangement—was nevertheless required as a precondition for benefiting from the collective bargaining agreement (para. 38). The Court observed that the applicant's objections, which were decisive for the outcome of the dispute, had not been adequately addressed. It concluded that the applicant had been subjected to an excessive and extraordinary burden by being excluded from the collective bargaining agreement on the basis of an unlawful employment relationship to which he was not responsible.

Within this framework, the Constitutional Court held that the domestic courts' decisions lacked relevant and sufficient reasoning and that the State had failed to fulfil its positive obligations concerning the protection of the union right. Accordingly, it found a violation of Article 51 of the Constitution and ordered a retrial as a means of redressing the violation (paras. 40–43).

Although the decision examined above concerns a seemingly technical and narrowly framed issue, it carries significant implications for the practice of Turkish labour law. The constitutional framework articulated by the Constitutional Court may enable a considerable number of employees working under sham subcontracting arrangements to benefit—albeit retrospectively—from collective bargaining agreements. In this sense, the decision not only rectifies an individual rights violation but also contributes to strengthening the effective protection of collective rights against structural abuses arising from unlawful employment arrangements.

6. MEDIATION AND THE RIGHT TO LEGAL REMEDIES:

Constitutional Court Decision (3/6/2025 – E. 2024/157 – K. 2025/121)

As also noted above in connection with various decisions, the effective exercise of the right to legal remedies has been becoming increasingly difficult for employees; particularly when factors such as information asymmetry are considered, the likelihood of success in the process of seeking legal remedies is diminished. With the aim of enabling employees to obtain their rights swiftly and through simplified procedures, the use of alternative dispute resolution mechanisms in labour disputes has come to the fore¹¹. The reflection of this trend in our country, has manifested itself in the introduction of mediation as a procedural prerequisite under Law No. 7036 on Labour Courts.

However, the regulation introduced with the aim of ensuring that workers attain their rights in a swift and a simple manner has, occasionally begun to result in the prolongation of legal-remedy-seeking processes and even in losses of rights for employees due to its detailed procedures. As a result of the referral of the problems encountered in labour proceedings with respect to mandatory mediation to constitutional review, the Constitutional Court has on several occasions held that the use of mediation in labour disputes is compatible with the Constitution, while also finding that its application in a manner that restricts the right to legal remedies is unconstitutional¹². The decision examined below, however, differs from the Court's previous case law in that it was brought before the Court by way of concrete norm review.

The dispute underlying the decision arose from a reinstatement action filed by an employee against the subcontractor following the termination of the employment contract. During the proceedings, it became apparent that the dispute involved an aspect of a principal employer–subcontractor relationship within the meaning of Article 2(6) of Labour Law No. 4857, or at least that the existence of such a relationship was contested. Pursuant to Article 3 of the Labour Courts Law No. 7036, referral to mediation constitutes a procedural prerequisite for filing a reinstatement action. Accordingly, in order for the court to examine the merits of the case, the mediation process must be conducted and concluded in compliance with statutory requirements.

The core reason why the dispute was brought before the Constitutional Court lies in Article 3(15) of the Labour Courts Law. This provision requires that, where a principal employer–subcontractor relationship exists and a mediation application is filed in relation to a reinstatement claim, both employers must jointly participate in the mediation meetings and align their intentions in order to reach a settlement. In practice, this rule obliges the employee to correctly identify the existence of a subcontracting relationship and its parties at the mediation stage. Where the nature of the relationship is clarified only during the trial phase, or where the mediation application is directed against an incorrect party, the case is dismissed on procedural grounds on the basis that the case condition has not been fulfilled.

In the context of the dispute, the Adana 6th Labour Court concluded that the rule to be applied—Article 3(15) of the Labour Courts Law—imposes an excessive and impractical burden of investigation and identification on the employee. The court found that this burden may disproportionately restrict the right of access to courts guaranteed under Article 36 of the Constitution, particularly in reinstatement actions, which are subject to strict time limits and require swift judicial protection. Accordingly, the court applied to the Constitutional Court by way of objection within the framework of concrete norm review and requested the annulment of Article 3(15) on the ground of its unconstitutionality.

The Constitutional Court examined the contested provision within the framework of the right to legal remedies and the right of access to courts. It noted that Article 3(15) effectively restricts access to judicial review by rendering mediation a strict case condition for reinstatement actions (para. 19). The Court first found that the restriction satisfied the requirements of legality and legal certainty, as it was prescribed by law and was sufficiently clear and foreseeable. However, it emphasised that this finding alone was insufficient, and that the restriction must also be assessed in terms of the principle of proportionality.

The Court accepted that the objective stated in the reasoning of the rule—namely, preventing disputes concerning party status in reinstatement actions by ensuring the joint participation of the principal employer and the subcontractor in mediation—constitutes a legitimate aim in constitutional terms (para. 26). Nevertheless, the Court stressed that proportionality requires not only suitability, but also necessity and proportionality stricto sensu (para. 29). In this regard, the Court referred to Article 124 of the Code of Civil Procedure No. 6100, which allows for the voluntary substitution of parties. This provision enables a reinstatement action filed against an incorrect or incomplete party to be redirected to the correct party, rather than being dismissed on procedural grounds. On this basis, the Court concluded that the contested rule was not necessary to achieve its stated objective (para. 31).

The Constitutional Court further assessed the severity of the burden imposed on the employee. It observed that the employee is required, at the mediation stage, to correctly identify a principal employer–subcontractor relationship to which the employee is not a party and which is often legally and factually unclear. Where this assessment is made incorrectly, the employee's opportunity to pursue a reinstatement action is entirely eliminated (para. 33). The Court held that this situation imposes an excessive and unbearable burden on the employee and renders the right of access to courts practically ineffective. It therefore concluded that a fair balance could not be struck between the public interest and the individual's right, and ruled that the provision violated the principle of proportionality safeguarded under Article 13 of the Constitution in conjunction with Article 36. Accordingly, Article 3(15) of the Labour Courts Law was annulled (paras. 34–35).

The decision under review is also of particular importance from the perspective of labour law, as it assesses mandatory mediation in employment disputes within the broader framework of the right to legal remedies. The Constitutional Court once again confirmed that mediation as a procedural prerequisite is not, in itself, contrary to the Constitution. However, it also clarified that where the mediation mechanism turns into a procedural obstacle to the detriment of the employee, a violation of the right to legal remedies may arise. In this respect, the decision provides important guidance for future regulation and application of mediation and other alternative dispute resolution mechanisms in labour disputes: such mechanisms must be applied in a manner compatible with the realities of working life, without restricting constitutional freedoms and while remaining proportionate. The Court's emphasis that mandatory mediation rules should be interpreted in light of their original purpose—namely, to enable employees to access their rights in a swift and simple manner—serves as a guiding principle for judicial authorities.

Footnotes

1 For sample decisions, See, Adem Erdem, A. No: 2018/13415, 29/6/2021; İsmet Murtezaoğlu, A. No: 2018/17312, 18/10/2022; Sercan Çelik, A. No: 2017/37350, 24/6/2020.

2 For similar decisions, See. Nasri Aydın, A. No: 2021/63276, 9/12/2025.

3 E.g. See. Aklime Aybek, A. No: 2022/66731, 30/7/2025; Zeldal Özdemir and others, A. No: 2020/373, 9/12/2025.

4 E.g., in the Ayla Demir İşat Application (2018/24245, 8/10/2020), which is referred to several times in the decision, it was concluded that the right to privacy guaranteed by Article 20 of the Constitution had been violated, and a decision was rendered in accordance with retrial.

5 For the concept of suspicion termination and its application in Turkish labour law in the pre–State of Emergency period, See, Kübra Doğan Yenisey, Şüphe Feshi, Sicil, September 2009, No. 11, pp. 65–72, at pp. 68–69; Ulaş Baysal, Şüphe Feshi Kavramı ve Şüphe Feshine İlişkin Yargıtay Kararlarının Değerlendirilmesi, Sicil, 2016; Canan Erdoğan, İş Hukukunda Şüphe Feshi, Ankara, 2019, p. 137 et seq.

6 Some of the decisions in which the Constitutional Court has set out the fundamental principles concerning Article 51 of the Constitution, that are also referred to in the judgment, are as follows: Anıl Pınar ve Ömer Bilge, A. No: 2014/15627, 5/10/2017, § 36; Ahmet Sefa Topuz ve diğerleri, A. No: 2016/16056, 21/4/2021, § 52; Barış Adıgüzel, A. No: 2016/15802, 8/9/2021, § 29.

7 Fort he cited decision, See, Court of Cassation 9. HD. 9/9/2024, E.2023/7508, K.2023/6118.

8 E.g. See, OECD Employment Outlook 2023, Artıfıcıal Intellıgence and The Labour Market, Paris 2023; ILO Flagship Report, The future of work Trade unions in transformation; Social Dialogue Report Peak-level social dialogue for economic development and social progress, Geneva 2024.

9 OECD Employment Outlook 2023, Artifıcial Intelligence and The Labour Market, s. 144.

10 For the former decisions in this direction, See, Muharrem Çimen, B. No: 2016/5002, 23/3/2023.

11 For a detailed ILO publishing on this issue, See, Ebisui, M./ Cooney. S./ Fenwick, C. (eds.), Resolving individual labour disputes: A comparative overview, Geneva 2016.

12 E.g. See,Gönül Aydan, A. No: 2020/39775, 28/11/2024; Yaşar Çıkrıkcı, A. No: 2020/36673, 17/7/2024.

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