EU Accession to the ECHR: The Challenges in Implementing the Accession Agreement at EU Level

Table of Contents: 1. Introduction. – 2. EU internal arrangements implementing international conventions. – 3. The provisions of the accession agreement that must be implemented at the EU level. – 3.1. The co–respondent mechanism and the role of the EU institutions in its implementation. – 3.2. The Prior Involvement of the CJEU. – 3.3. Inter–party cases and the EU internal rules. – 3.4. The election of judges to the ECtHR on behalf of the EU. – 4. The adoption procedure for the EU Internal rules. – 5. Conclusion.

Abstract: The accession of the EU to the ECHR is a complex process. An accession agreement was negotiated between the Council of Europe (CoE) member states and the EU. The agreement regulates the external dimension of the accession, the incorporation of the EU into the Convention system. The agreement delegates to the EU institutions, the competence to implement some of its key provisions, regarding the co-respondent mechanism, prior involvement and others. During the negotiations, the EU choose to internalise many aspects related to the application of the accession agreement, to protect the autonomy of the EU legal order from the jurisdiction of the ECtHR. The internal arrangements implementing the accession agreement will primarily take the form of a set of internal rules and a code of conduct which expand on the provisions of the accession agreement. In the wake of Opinion 1/25, the biggest missing gap in the accession framework is the lack of clarity regarding the internal allocation of decision-making powers between EU institutions to implement the accession agreement. This article attempts to address this gap by analysing the EU’s internal rules and other aspects related to the implementation of the accession agreement at EU level. It brings together available information on this topic from the 2013 and 2023 rounds of negotiations, as well as from the hearings in Opinion 2/13.

Keywords: EU accession to the ECHR – EU internal rules – EU Commission – EU Council – Opinion 1/25 – Accession Agreement.

1.   Introduction

The accession of the European Union (EU) to the European Convention on Human Rights (the Convention or ECHR) is a complex process. The EU will be incorporated into the Convention System, once the Agreement on the Accession of the EU to the Convention (the accession agreement) is ratified by the Council of Europe (CoE) member states and by the EU.[1] The accession package is comprised of several documents. One is a draft declaration by the EU to be made at the time of signing the accession agreement.[2] A draft rule to be added to the Rules of the Committee of Ministers (CoM) for supervising the execution of judgements and the terms of friendly settlements in cases involving the EU.[3] A draft model memorandum of understanding between the EU and CoE non–EU member states.[4] Finally, there is a draft explanatory report to the accession agreement.[5]

The accession package was negotiated between the CoE member states and the EU, and will regulate the external dimension of the accession, in particular the relation between the EU and the Convention system. It covers topics such as the conditions for submitting joint applications (the co–respondent mechanism) against the EU and its member states to the European Court of Human Rights (ECtHR), the activation of the prior involvement of the Court of Justice of the European Union (CJEU), inter–party applications between EU member states, electing judges to the ECtHR on behalf of the EU, and more.

The EU’s accession to the ECHR must also be regulated internally, at the EU level.[6] During the negotiations of the accession agreement, the EU chose to internalise many decision-making processes, to limit the jurisdiction of the ECtHR to interpret key provisions of the accession agreement, to protect the autonomy of the EU legal order. The accession agreement delegates to the EU institutions, the competence to apply some of its key provisions regarding the co-respondent mechanism, the prior-involvement mechanism and inter-party applications between EU member states.

The EU’s strategy, to internalise the above-mentioned mechanisms, has generated a different set of issues, related to the allocation of competences to implement the agreement, between the EU member states, the Commission, and the Council. The EU institutions are negotiating the division of competences to implement the accession agreement. However, due to the different interests of each institution, they find it difficult to agree on how to divide the competence to implement the agreement and cannot decide the precise content of the internal rules and the code of conduct.

To fully grasp how some aspects of the EU’s accession to the ECHR will work in practice, it is important to understand how the EU will apply the accession agreement internally. This topic is important not only for the EU but also for the Convention System and for the ECtHR, because important aspects on the applicability of the agreement depend on the EU.[7] Pergantis wrote that the accession agreement refers to the EU internal rules, but because their content is unknown, this creates gaps in the whole picture for the EU’s accession to the ECHR.[8] In this article I want to address the following question: What challenges do the EU institutions face in implementing the accession agreement to the ECHR at the EU level?

This article comes in the context in which, in November 2025, the EU Commission submitted another request for an opinion to the CJEU, Opinion procedure 1/25, on the compatibility of the 2023 accession agreement with EU law.[9] The request was submitted more than two years after the second round of negotiations (2020-2023) had concluded. When the first round of negotiations (2010-2013) concluded, the EU Commission did not wait so long to submit the request to the CJEU. The main reason for the long period between the conclusion of the second round of negotiations and the submission of the request was that the EU wanted to finalise the internal arrangements implementing the agreement.[10]

We are currently in the final stages of accession, yet we know almost nothing about how decision-making powers are allocated internally between EU institutions under the accession agreement. While most authors consider the CJEU’s opinion procedure and the CFSP issue to be the main obstacles to accession, other issues concerning the EU internal arrangements remain unexplored. This aspect of accession is often overlooked by many commentators. There is limited information available on this topic, because discussions within the EU Council are not public. A limited number of EU internal documents, from the first round of negotiations mention the EU internal rules, the code of conduct and other aspects important for the implementation of the accession agreement. The topic was also addressed during the proceedings for Opinion 2/13 and during the second round of negotiations.

This article has the following structure. Section 2 analyses similar internal arrangements adopted to implement particular aspects of EU-signed conventions. This part compares the implementing arrangements for the EU’s accession to the ECHR, with those for the EU’s accession to the Council of Europe Convention on Preventing and Combating Violence against Women and Domestic Violence (the Istanbul Convention) and the United Nations Convention on the Rights of Persons with Disabilities (CRPD). Section 3 looks at the provisions of the accession agreement which must be implemented at the EU level. This part will explore the importance of the EU internal rules and code of conduct for the functioning of the co–respondent mechanism, the prior involvement of the CJEU, Inter–party applications and the election of judges to the ECtHR on behalf of the EU. Section 4 looks at the adoption procedure of the EU Internal rules and code of conduct, to outline the challenges which can arise from the adoption of the legislation implementing the accession agreement to the ECHR. Section 5 concludes.

2.   EU internal arrangements implementing international conventions 

Adopting measures to implement international conventions that the EU is party to is nothing new. Such implementing measures are important for Conventions which are binding on the EU and its institutions as an international organisation, for example the Istanbul Convention[11] or the CRPD.[12] Such conventions, require the EU to participate in monitoring bodies and to submit periodic reports regarding the fulfilment of its obligations. Because the EU member states are also signatories to those Conventions, the participation of the EU and its member states must be regulated at the EU level, to ensure that they implement their obligations in their fields of competences or that reporting duties are not doubled. 

The implementing measures take different forms, but usually the Council adopts Codes of Conduct which apply to the EU Commission, member states and the Council. The Codes of Conduct are purely internal, and they detail the modalities in which the EU institutions and its member states will fulfill their implementing, reporting, and monitoring obligations, mainly in areas of shared competences and the participation in convention monitoring bodies.

For example, when the EU signed the Istanbul Convention, it adopted a Code of Conduct to regulate its own participation, as well as that of its member states, under the Convention bodies and mechanisms. The Code of Conduct establishes the cases when the EU and the member states can report on areas covered by shared competences to avoid double reporting to the Group of Experts on Action against Violence against Women and Domestic Violence (GREVIO) and the need to coordinate their positions when they participate in the works of GREVIO. Similarly, the CRDP Code of Conduct sets out the internal arrangements for implementing the CRDP at EU level. The Code of Conduct regulates the Commission’s role as the focal point for implementing the CRDP on behalf of the EU, the EU’s representation before the treaty body and voting arrangements. 

For the EU’s accession to the ECHR, the process was similar. During the first round of negotiations, the EU’s internal discussions focused on a set of internal rules, because it was clear to the EU institutions that the accession agreement cannot regulate practical and political aspects which apply to them. At that stage they only agreed on a set of principles and what aspects of the accession agreement should be regulated at the EU level.[13] The basic principles show the wide range of issues to be addressed by the EU internal rules both legal and political.[14]

As the EU institutions had not made progress on how to implement the agreement at EU level, some EU member states and the EU Council suggested during the hearings for Opinion 2/13 that the request for an opinion might be inadmissible with regard to aspects relating to EU internal rules.[15] The CJEU decided that the EU internal rules are irrelevant for the opinion procedure, and cannot be subject to review under Article 218 Treaty on the Functioning of the European Union (TFEU), because they constitute internal EU law.[16] As the 2013 accession agreement was not approved, a new round of negotiations was required and the EU’s internal arrangements were put on hold until the new agreement was finalised.[17]

Now that the accession framework was finalised, the EU institutions must put in place, the internal arrangements implementing the accession agreement to the ECHR. However, due to the specific nature of the Convention system and the complex provisions of the accession agreement, the internal arrangements must fulfil a much broader role, than the above-mentioned Codes of Conduct. The internal arrangements must regulate the allocation of the decision-making powers for the applicability of the mechanisms created by the accession agreement. 

Normally, the ECtHR would have the competence to interpret and apply the mechanisms from the accession agreement, because they will amend the ECHR. The CJEU rejected this option, consequently the application of the agreement is in the hands of the EU member states, the Commission, and the Council. As might be expected, EU institutions are finding it difficult to agree on the internal allocation of competences. It is difficult for them to predict and regulate all types of issues which might arise from the implementation of the accession agreement. These institutions have different interests, regarding the situations when the co-respondent mechanism can be activated, or if the EU has exclusive or shared competences in a case submitted before the ECtHR. While it is difficult to identify the full scope of the internal arrangements implementing the agreement at the EU internal level, the next part looks at those aspects, delegated to the EU by the accession agreement.

3.   The provisions of the accession agreement that must be implemented at the EU level

The accession agreement, delegates to the EU, the competence to implement, trough EU internal rules and the code of conduct, the co-respondent mechanism, the prior involvement of the CJEU, the procedure for the election of judges to the ECtHR on behalf of the EU, and the inter–party cases assessment. According to documents published by the EU, the internal rules have the function of regulating the role of the EU Council towards the EU Commission after the EU’s accession to the ECHR.[18] The representation of the EU before the ECtHR is also important here, because the institution representing the EU, will play a central role in implementing the accession agreement.[19] According to the positions expressed during the hearings for Opinion 2/13, the EU will be represented by the EU Commission before the ECtHR.[20] The EU member states will be represented by a single agent, something regulated by the EU internal rules.[21]

3.1.  The co–respondent mechanism and the role of the EU institutions in its implementation 

The accession agreement introduces the co-respondent mechanisms to ensure that joint applications submitted to the ECtHR are correctly addressed to the EU or its member states.[22] According to the explanatory report ‘To implement the Accession Agreement, the EU will adopt internal legal rules regulating various matters, including the functioning of the co-respondent mechanism’.[23]

The activation of the co-respondent mechanism is subject to tests found in Article 3 paragraphs 2 and 3 of the accession agreement:

“2. Where an application is directed against one or more member states of the [EU], the [EU] may become a co-respondent to the proceedings …notably where [the] violation could have been avoided only by disregarding an obligation under European Union law.

3. Where an application is directed against the [EU], the [EU] member states may become co-respondents … notably where [the] violation could have been avoided only by disregarding an obligation under the… [Treaty on the European Union, the Treaty on the Functioning of the European Union or any other provision having the same legal value]”. 

Paragraph 5 regulates the procedure for the activation of the co-respondent mechanism: ‘5. […] The [ECtHR] shall admit a co-respondent by decision if a reasoned assessment by the [EU] sets out that the conditions [from paragraph 2 or 3] […] are met’.[24]

The EU has an important role in the applicability of the co–respondent mechanism because its activation[25] and termination[26]depend on assessments created at the EU internal level and presented to the ECtHR. In other words, the EU will decide on the interpretation of the tests, tacking into account the accession agreement and the explanatory report. The clauses on the co–respondent mechanism are self-judging clauses, because their applicability depends on the EU.[27]

According to the explanatory report, the assessments presented by the EU, must be considered ‘as determinative and authoritative’by the ECtHR.[28] Tobias Lock wrote that this makes the EU the ‘gatekeeper’ of certain procedural aspects introduced by the accession agreement.[29] The role of the ECtHR or its ability to review the assessment presented by the EU is also interesting. The ECtHR is expressly excluded from questioning the assessment presented by the EU.[30] The accession agreement does not mention the ECtHR’s competence to review the assessments.[31] Simply put it, the ECtHR will have to issue decisions mirroring the assessments presented by the EU, without any review. The procedural decision rests completely within the EU.[32]

In this context, the EU internal rules will regulate into greater details the conditions under which the EU and its member states can join as co-respondents expanding on Article 3 paragraphs 2 and 3 of the accession agreement. They will also regulate the procedure under which the EU will create the assessment mentioned in paragraph 5. The internal rules implementing the co–respondent mechanism at the EU level, are important for the Convention system, the ECtHR and for the applicant. If the EU adopts a restrictive approach to the tests regarding the co-respondent mechanism, the advantages of this mechanism will not materialise for the applicant, and the gap in the accountability before the ECtHR will persist after the accession.[33]

Under the 2023 accession agreement, when the co–respondent mechanism applies, the ECtHR can only hold jointly responsible the respondent and co–respondent for violating the ECHR.[34] The EU internal rules are also important for the attribution of responsibility between the respondent and co-respondent. The specific division of the afforded satisfaction by the ECtHR, will be regulated by the EU internal rules.[35] Similarly, the EU internal rules will set out the conditions when both the EU and member states can refer to the Grand Chamber when the co-respondent mechanism applies.[36] Most likely, referrals to the Grand Chamber will be submitted in a coordinated manner.

What happens when the EU Council and the EU Commission disagree on the implementation of the tests triggering of the co-respondent mechanism, or on the specific division of the afforded satisfaction? Are there any checks and balances within the EU to ensure that the provisions of the accession agreement are implemented correctly?

Initial EU Council documents referred to a mechanism to settle disagreements without referring the issues to the CJEU.[37] EU internal documents refer to ‘rules on joint friendly settlements’. It remains to be seen how this mechanism will work in practice, and how the EU Commission and EU Council will settle their disagreements on the applicability of the co-respondent mechanism. In Opinion 2/13, the CJEU stated that any agreement between the respondent and the co-respondent must be reviewed by the CJEU according to relevant EU internal law.[38] The CJEU mentioned this the context of the attribution of responsibility between the respondent and co–respondent, which was excluded from the 2023 version of the accession agreement. It remains to be seen whether such settlement mechanism will be included in the final version of the EU internal rules and if the CJEU will approve it. These institutional disagreements cannot be taken before the ECtHR, because the EU institutions and its member states must coordinate their positions. The Code of Conduct will regulate the conduct of the respondents before the ECtHR.[39]

In conclusion, the EU internal rules expand on the provisions of the accession agreement and will regulate into greater detail the activation and termination of the co-respondent mechanism, the conduct of the EU and its member states during the proceedings before the ECtHR, the specific division of the satisfaction afforded by the ECtHR, and a mechanism for settling institutional disputes. The EU internal rules are important for the applicant and for the ECtHR because the effectiveness of the co-respondent mechanism depends on them.

3.2.  The Prior Involvement of the CJEU 

Closely related to the co-respondent mechanism is the prior involvement of the CJEU.[40] The prior involvement mechanism was introduced in the accession agreement, to ensure that the ECtHR does not rule on the compatibility of a provision of EU law with the ECHR, without the CJEU having had the opportunity to do so.[41] The functioning of the prior involvement mechanism will be regulated by the internal rules. According to Article 3 paragraph 7 of the accession agreement: 

“7. […] if the [CJEU] has not yet assessed the compatibility with the rights at issue defined in the Convention or in the Protocols […] of the provision of [EU] law […] sufficient time shall be afforded by the [ECtHR] for the [CJEU] to make such an assessment […] The [EU] shall ensure that such assessment is made quickly so that the proceedings before the [ECtHR] are not unduly delayed […]”.

According to the explanatory report, insofar as possible the EU assessment on the co-respondent mechanism, will address the issue of the prior involvement of the CJEU.[42] For the ECtHR, the EU assessment on the necessity to activate the prior involvement, and the interpretation of the caselaw of the CJEU included in it, will also be considered as ‘determinative and authoritative’.[43]

According to EU Council documents, the EU internal rules will regulate the procedure for the functioning of the prior involvement mechanism, the competent EU institution to initiate and conduct the proceedings before the CJEU.[44] At the level of the CJEU, to be made functional, the prior involvement will require amendments to the Statute.[45] The explanatory report to the accession agreement states that the existing accelerated procedure before the CJEU should be used for the prior involvement, which takes between six to eight months, to ensure that the proceedings before the ECtHR are not unduly delayed by the prior involvement.[46]

The prior involvement procedure is similar to the preliminary ruling procedure, except for one major difference. In the preliminary ruling procedure, national courts formulate questions for the CJEU. It remains to be seen whether the EU Commission will refer questions to the CJEU, or if the CJEU will receive the application that the ECtHR has notified to the EU and its member states. The current practice is that the registry of the ECtHR communicates the individual complaints to the parties with a set of questions relevant for the examination of the complaint. This will give the ECtHR the opportunity to raise questions that can be addressed during the prior involvement of the CJEU. Most likely the EU internal rules will address all these details relating to the practical functioning of the prior involvement.

3.3.  Inter-party cases and the EU internal rules 

The accession agreement, in Article 4 Inter-Party cases, states that the EU and its member states shall not avail themselves of Article 33 of the ECHR. In Opinion 2/13, the CJEU wanted to exclude the jurisdiction of the ECtHR, for Article 33 inter-party cases, which concern the interpretation and application of EU law.[47] To address this objection, paragraph 4 states the following:[48] ‘4. The [ECtHR] shall provide the [EU] upon request with sufficient time to assess, as a matter of priority, whether and to what extent an inter-party dispute under Article 33 of the Convention between member states of the [EU] concerns the interpretation or application of [EU] law’.

The EU can request to create an assessment on what parts of the inter-party application concern EU law. The assessment will be presented to the ECtHR. Those parts which concern EU law, will not be analysed by the ECtHR.[49] Most likely, the EU internal rules will regulate the procedure and conditions under which the EU will forward such requests to the ECtHR, and the procedure for the creation of the assessments.

The applicability of the EU internal rules on this topic relates to existing EU proceedings. According to the negotiations documents, the EU Commission will most likely be required to initiate proceedings under Article 258, for a failure of member states to fulfil their obligations, which can result in infringement proceedings before the CJEU, to determine whether Article 344 was circumvented.[50] After these proceedings are finalised, the EU Commission will submit the conclusions to the ECtHR, with the finding of the CJEU that the inter–party complaint, lodged to the ECtHR, concerns EU law.[51]

This article is expected to be applied in exceptional circumstances, when EU member states initiate external settlement proceedings without consulting the EU institutions. Under the existing EU practice, reiterated in the Mox Plant judgment, the EU member states have the obligation to inform the EU Commission prior to initiating proceedings to external dispute settlement mechanisms which might fall under the competence of the CJEU.[52] In other words, the EU member states have the general obligation to consult the Commission prior to submitting their application to the ECtHR. Nonetheless, the accession agreement gives the EU the competence request the ECtHR to strike out inter-party applications, when the EU member states did not respect their obligations under Article 344 TFEU, if this is confirmed by the CJEU.[53]

3.4.  The election of judges to the ECtHR on behalf of the EU 

According to the accession agreement, the election of judges on behalf of the EU to the ECtHR, will be regulated by EU internal rules which will define the modalities for the selection of a list of candidates to be submitted to the CoE Parliamentary Assemble.[54] The EU internal rules on this topic, will implement the existing CoE rules and standards regarding the appointment of judges to the ECtHR. More precisely, the internal rules will establish the internal selection procedure (the call for candidates, interviews for the candidates, linguistic abilities assessment procedure, etc.).[55]

The condition for the internal rules on this topic, is that they have to respect the current framework followed by the contracting parties to the ECHR. The language of the accession agreement is broad, to allow the EU to incorporate current but also future instruments on the topic. The EU will be consulted, on any changes to the instruments which it adopted, or it will want to adopt.[56]

It is unclear whether the EU internal rules on this topic will be included in the same set of rules as the co-respondent mechanism, prior involvement and inter-party cases, or if they will be adopted in separate legal instruments. 

4.   The adoption procedure of the EU internal rule and measures implementing the accession agreement

The explanatory report to the accession agreement states that ‘[t]o implement the Accession Agreement, the EU will adopt internal legal rules regulating various matters’.[57] The adoption procedure of the internal rules was addressed during the hearings for Opinion 2/13. The EU institutions and EU member states had different opinions and could not agree on how to implement the accession agreement and what procedure to use to adopt the internal rules. Different provisions regulate the adoption of the accession agreement, first at the CoE[58] level, second at the EU level, and third at the EU member states level.

The adoption of the EU internal rules is closely connected to the adoption of the accession agreement at the EU and EU member states level. The adoption of the agreement on the EU’s accession to the ECHR is regulated expressly by the TFEU. According to Article 218(6)(a)(ii) TFEU, for the conclusion of the accession agreement, the EU Council must adopt a unanimous decision, after obtaining the consent of the EU Parliament. This provision, read in conjunction with Article 289 TFEU, shows that for the adoption of the EU Council decision concluding the accession agreement, the special legislative procedure must be followed. The EU Council is the only legislator, but the EU Parliament must consent for the adoption of the decision.[59] Paragraph eight adds that the EU Council decision, concluding the accession agreement, will enter into force after the EU member states approve it according to their constitutional procedures.

The EU Commission mentioned during the hearings for Opinion 2/13, that the procedure for the prior involvement would be regulated by the EU internal rules which would be included in the EU Council decision concluding the accession agreement pursuant to Article 218.[60] If the position expressed by the EU Commission is still valid, the approval of the accession agreement and the EU internal rules will be included in the same EU Council decision. And both documents will enter into force once the EU member states approve them according to their constitutional procedures. 

Some EU member states disagreed with the position expressed by the Commission while others supported it. These discussions took place in the context of the prior involvement mechanism. For example, the Polish government[61] argued that the prior involvement and the capacity of the EU Commission to initiate the proceeding must have a specific basis in the Treaty.[62] On the other side, the French, Austrian, Danish and German governments considered that treaty amendments are not necessary, because the EU Council decision will be adopted according to the constitutional requirements of the EU member states.[63] The Netherlands Government, added that the prior involvement should be regulated directly by the Statute of the CJEU, not by the Council decision concluding the accession agreement.[64]

Similarly, AG Kokott in her views on the accession agreement, wrote that the implementation of the procedure for the prior involvement, requires amendments to the Statute of the CJEU.[65] According to her, the prior involvement cannot be adopted only by the Council decision, because it bypasses the ordinary legislative procedure necessary to amend the Statute of the CJEU under Article 281 TFEU, which requires the involvement of the EU Council and EU Parliament.[66]

According to the EU Parliament, the EU Council decision will conclude and give legal force to the accession agreement.[67] The EU Parliament questioned whether the EU Council decision and internal rules can have normative content because they are not subject to amendment by the Parliament.[68] The EU Parliament also considered that the legislative procedure should be used to implement the provisions of the accession agreement. 

These debates show that, at the time, there was no consensus on whether the internal rules are sufficient to implement the accession agreement, or on their adoption procedure. It remains to be seen if measures implementing the accession agreement will be included in the same EU Council decision (which must be adopted unanimously and with the consent of the EU Parliament), which will enter into force once the EU member state approve it according to their constitutional procedures, or if they will be adopted via the legislative procedure. Some of the provisions in the accession agreement that depend on existing legal instruments may be implemented via the ordinary or the special legislative procedures, depending on the instrument which they amend. For example, the procedure for prior involvement will most likely be introduced in the CJEU Statute, as set out in Article 281 TFEU.

5.   Conclusion

Once the negotiations for the 2023 accession agreement had concluded, it seemed that the accession process was coming to an end. More than three years later, we are still waiting for the final outcome. Furthermore, many important aspects of the accession framework remain uncertain. Key issues relating to the implementation of the accession agreement remain unresolved due to the complex matters delegated by the accession agreement to the EU institutions. The EU’s strategy to internalise the implementation of the main provisions of the accession agreement, gave rise to a different set of obstacles. Particularly concerning the allocation of decision-making powers between the EU member states, the Commission, and the Council. 

For previous EU-signed conventions, adopting the implementing measures was not so challenging because they dealt with reporting and coordination of positions at the EU level, which are less complex than the EU’s internal arrangements for accession to the ECHR. Even back in 2013, the EU institutions could not finalise the internal arrangements, and the 2023 version of the accession agreement is even more complex. One thing is certain; the EU internal rules will regulate legal and political issues. They are an integral part of the accession framework because the functioning of the accession agreement depends on them. 

During the first round of negotiations, most EU member states and institutions did not consider the EU internal rules essential to the accession process. However, during the hearings for Opinion 2/13, some member states argued that the EU internal rules are important, their opinions did not prevail.

The new Opinion procedure 1/25 is underway. The CJEU will most likely be faced with questions relating to the implementation of the mechanisms set out in the accession agreement. The ECtHR will also give an opinion on the agreement for the EU’s accession to the ECHR.[69] The ECtHR must understand the EU’s internal implementing arrangements, to have a complete picture of how the mechanisms introduced by the accession agreement will work in practice.[70] I would argue that the current uncertainty provides an insight into how EU membership would affect the Convention system. This is because important decisions related to the applicability of the accession agreement are decided at the EU level behind closed doors. The EU’s internal implementation of the agreement is important not only for EU institutions but also for applicants, the procedure before the ECtHR, and the overall effectiveness of the Convention system in cases involving the EU.