Prohibition Of Filing A Lawsuit Under Article 18/5 Of The Turkish Mediation Law And The Question Of Unconstitutionality

I.Introduction

Article 18/5 of the Law No. 6325 on Mediation in Civil Disputes [the “Mediation Law”] introduces the following provision:

"""In the event that an agreement is reached at the end of the mediation activity, the parties may not file a lawsuit on the agreed matters."""

With this provision, the legislator aimed to make the agreements reached in mediation binding and to reduce the court burden. However, the regulation has been controversial from the beginning due to its nature that directly limits the right of access to the court.

1. Approaches of the Court of Cassation Regarding Lawsuits Filed Against Mediation Agreement Documents

The case law of the Court of Cassation has adopted a "narrow interpretation" approach to soften the harshness of Art. 18/5. In this respect:

• In the decision of the 9th Civil Chamber dated 29.02.2024 (2024/2065 E., 2024/3897 K.), it was stated that the prohibition of filing a lawsuit limits the right of access to the court, and for this reason, it was stated that in cases where the issues are not clearly stated in the agreement document, it cannot be accepted that the mediation activity ended with the agreement.
• Similarly, in its decision dated 10.10.2024 (2024/10147 E., 2024/13332 K.), it was concluded on the same grounds that minutes in which the "agreed matters" are unclear will not give rise to a prohibition of litigation. Thus, the Court of Cassation has made the element of certainty a prerequisite for the applicability of the non-suit clause.

This approach also manifests itself in terms of the dispute clause:

• In its decision dated 13.01.2025 (2024/13061 E., 2025/348 K.), the 9th Civil Chamber clearly emphasized that a concrete dispute must first arise in order to enforce the prohibition of litigation. The decision dated 24.04.2025 (2025/2403 E., 2025/3786 K.) stating that the minutes prepared in voluntary mediation meetings held at the initiative of the employer before the dispute arises are not binding should also be mentioned within this framework. In this way, the Court of Cassation tries to limit practices that are particularly open to fraudulent misuse of will in employee-employer relations.

On the other hand, the 3rd Civil Chamber of the Court of Cassation, in its decision dated 02.12.2024 (2024/971 E., 2024/4021 K.), stated that the aim of the legislator is to ensure that these issues are not subject to litigation as long as the agreement minutes are valid. However, in the same decision, it is also accepted that the minutes may be annulled for reasons such as forgery of the signature, fraud of will or procedural irregularity. This statement reveals that the prohibition of litigation is not absolute, but depends on the existence of an agreement document whose validity is undisputed.

III. The Prohibition of Filing a Lawsuit Against the Mediation Agreement Document Violates the Rights and Freedoms Protected by the Turkish Constitution

This line of jurisprudence shows the tension between Art. 18/5 and the freedom to seek rights guaranteed under Art. 36 of the Turkish Constitution. Although the Court of Cassation tries to protect the essence of the right through narrowing interpretations, the wording of the regulation is susceptible to broad application. For this reason, the risk of violation of the freedom to seek rights is directly linked to the article itself, not to judicial interpretations. Moreover, in practice, the existence of situations where the parties may not have equal bargaining power increases the risk of limiting the right of access to court.

In this context, it is possible that there are situations where a mediator agreement document, which is formally drafted in accordance with the Mediation Law and the relevant legislation, is invalid due to various circumstances of the parties. One of the most important of these situations is will defects.

The document signed as a result of one of the parties to the mediation agreement taking advantage of the difficult situation of the other party, one party deceiving or intimidating the other party, or the parties making a mistake is not legally valid. In cases where these circumstances arise after the date of signature of the agreement document, the parties will have no natural right to request the annulment of the agreement document, since the consequences of a document that is not legally valid may have dangerous consequences in any case.

In this case, in cases where the parties request the annulment of an agreement document based on grounds of invalidity such as the above-mentioned grounds, the rejection of this request on the grounds that there is a prohibition to file a lawsuit based solely on Article 18/5 of the Mediation Law would, in the simplest terms, constitute a violation of the freedom to seek rights guaranteed by Article 36 of the Constitution.

This issue has been the subject of various studies and discussions in the doctrine. Prof. Dr. Mine Akkan has examined the nature of the regulation in question and stated that it is not a condition of litigation, but rather a special manifestation of the concept of legal interest. According to Akkan, as long as there is a valid agreement document, a lawsuit cannot be filed on the same subject; however, the invalidity of the agreement may be asserted in cases such as fraud, forgery and violation of mandatory rules. In this case, the prohibition of filing a lawsuit will disappear and the court will be able to resolve the dispute.[1]

Prof. Dr. Lecturer. Prof. Dr. Ayşe Karaca Öz examined the issue especially in terms of the cases where the agreement document is unlawful due to undue advantage. According to the author, in the event that one of the parties abuses its economic or social superiority and shapes the agreement in its own favor, there cannot be a real compromise. For this reason, the prohibition of litigation stipulated by Art. 18/5 cannot be applied to mediation agreements that are annulled due to undue advantage. Giving binding effect to such a document is incompatible with the principles of voluntariness and balance of interests of mediation.[2]

Prof. Dr. Muhammet Özekes also considers Article 18/5 of the Mediation Law problematic in terms of the freedom to seek rights and the principle of proportionality. The author emphasizes that the essence of mediation is voluntariness, and in this context, the rule that "no lawsuit can be filed on the agreed matters" narrows the parties' right to resort to judicial remedies. While the agreement document is already recognized as a judgment and enforceable, the prohibition of filing a lawsuit constitutes a disproportionate limitation in terms of the freedom to seek rights.

Özekes also observes that the prohibition of filing a lawsuit may have consequences against the weaker party in practice, especially in employee-employer disputes. In the event that agreements signed under pressure from the employer are supported by a prohibition of litigation, even if the employee's will has been frustrated, the possibility of resorting to a judicial remedy may be effectively closed. This situation is contrary to both the voluntary principle of mediation and the freedom to seek rights guaranteed under Article 36 of the Constitution.

For these reasons, the author stated that Art. 18/5 cannot be applied in an absolute manner and that it should be reinterpreted by considering the freedom to seek rights and the principle of proportionality.[3]

1. Conclusion

At this point, it is seen that the limitations imposed by the narrow interpretation of the Court of Cassation do not eliminate the constitutional drawback inherent in the regulation. It is a disproportionate limitation to stipulate the prohibition of filing a lawsuit when the agreement documents are already enforceable.

In conclusion, although Article 18/5 of the Mediation Law aims to increase the effectiveness of the mediation institution, it is a regulation that limits the freedom to seek rights and damages the equality of the parties' wills.

Therefore, the prohibition of filing a lawsuit regulated under Article 18/5 of the Mediation Law should be annulled as it disproportionately restricts the freedom to seek remedies and is conducive to abuse. Only with such an annulment, mediation will be able to continue to function as a settlement method based on the voluntary will of the parties and compatible with constitutional rights.

[1] AKKAN Mine, Prohibition and Consequences of Filing a Lawsuit on the Matters Agreed at the End of the Mediation Activity, Dokuz Eylül University Journal of Faculty of Law, Vol. 20, No: 2, Izmir 2018, pp. 1-31

[2] KARACA ÖZ Ayşe, Cancellation of the Mediation Agreement Document on the Grounds of Excessive Use, Sakarya University Journal of Faculty of Law, December 2023, p. 1424 et seq.

[3] ÖZEKES Prof. Dr. Muhammet, Evaluation of Mandatory Mediation in terms of Freedom of Right Search and Mediation Principles - A Critical Approach to Mandatory Mediation, International Mediation Symposium Proceedings, 2020.