The Notion of “Shared Responsibility” and its Radical Impact on the Relationships between the ECtHR and the Domestic Authorities

By Dr Lorenzo Acconciamessa

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A note from the team:

To celebrate the 15th anniversary of the Strasbourg Observers Blog, we organised an in-person symposium with scholars, practitioners, and members of the ECtHR on 8–9 May 2025 in Ghent. Connecting in person with so many regular contributors was a wonderful experience and led to engaging dialogue with current and former judges of the Court. To allow our online community to participate in the thought-provoking discussions that took place, we will be publishing selected position papers on the blog over the next two summer months. We wish all of our readers a well-deserved break with a little peek on Strasbourg Observers here and there.

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Introduction: From “Subsidiarity” to “Shared Responsibility”

In 1968, in the Belgian Linguistic Case the European Court of Human Rights (‘the Court’) held that it cannot ‘lose sight of the subsidiary nature of the international machinery of collective enforcement established by the [European] Convention [on Human Rights]’ (‘the Convention’; para. 10). Complemented in Handyside v. the United Kingdom ([Plenary], 1976, para. 48), through the doctrine of the margin of appreciation, subsidiarity has been unanimously recognised as ‘one of the corner-stones of the Court’s case-law’ (Akdivar and Others v. Turkey [GC], 1996, Dissenting opinion of Jusge Gölcüklü, para. 11).

In the last 15 years, during which the system has been reformed, subsidiarity has been complemented by the new (and still underexplored) notion of ‘shared responsibility’ (Gerards, 2014): the 2010 Interlaken Declaration called for a ‘strengthening of the principle of subsidiarity’ and stipulated for the first time that it ‘implies a shared responsibility between the State Parties and the Court’. In 2011, in the Izmir Declaration, the Member States recalled ‘the shared responsibility […] in guaranteeing the viability of the Convention mechanism’, and invited the Court to give practical effect to subsidiarity (also) through a careful application of the admissibility criteria. The 2012 Brighton Declaration encouraged an open dialogue between the Court and States Parties with the purpose of ‘developing an enhanced understanding of their respective roles in carrying out their shared responsibility’. To this end, Member States decided that a reference to subsidiarity and the margin of appreciation should be included in the Preamble, and that they would have given the Court a power to allow such dialogue (Protocol No. 16 on the advisory jurisdiction). The 2015 Brussels Declaration recalled the ‘primary role played by national authorities’.

In 2018, the Copenhagen Declaration clarified that ‘[t]hroughout the reform process, the term shared responsibility has been used to describe the link between the role of the Court and the States Parties’ with the aim of ‘achieving a balance between the national and European levels’, and stipulated that ‘[f]or a system of shared responsibility to be effective, there must be a good interaction between the national and European levels’, and a ‘constructive and continuous dialogue’. This declaration also praised the Court for its ‘continued strict and consistent’ application of the admissibility criteria, ‘including by requiring applicants to be more diligent in raising their Convention complaint domestically’.

In 2021, Protocol no. 15 entered into force, and incorporated into the Preamble a reference to subsidiarity, the State authorities’ primary responsibility and their margin of appreciation. Most recently, subsidiarity and shared responsibility were reiterated in the 2023 Reykjavik Declaration and in 2024 were defined by the Court, next to democracy, as the fundamental features of the European public order (Verein KlimaSeniorinnen Schweiz and Others v. Switzerland [GC], 2024, para. 411).

As this brief summary makes clear, the notion of shared responsibility advocates, on the one hand, for a more self-restrained approach from the Court, based on the trust it should place on the domestic authorities and their willingness and capability to implement the Convention, and, on the other hand, for a more proactive role for domestic authorities themselves, which are expected to actively engage with the Convention and prevent cases from reaching Strasbourg. And indeed, both those ideas have been incorporated into the Court’s case-law.

‘Shared Responsibility’ as Requiring Strasbourg’s Self-Restraint

On the basis of the notion of shared responsibility, the Court has progressively developed a posture of self-restraint, emphasising the domestic authorities’ primary responsibility.

First of all, it has responded to the invitation to give effect to subsidiarity by strictly applying the admissibility criteria. In this regard, the Court has significantly raised the standard of diligence required from applicants in the process of exhausting the domestic remedies (Glas, 2023; Acconciamessa, 2025): it held that ‘[e]ven in those jurisdictions where the domestic courts […] are able, or even obliged, to examine the case of their own motion […], applicants are not dispensed from raising before them a complaint which they may intend to subsequently make to the Court’ (Fu Quan, s.r.o. v. the Czech Republic [GC], 2023, para. 171), and that for this purpose it is not sufficient for a violation to be ‘evident’ (Grosam v. the Czech Republic [GC], 2023, para. 90). On this basis, the Court dismissed complaints which had not been properly raised domestically, notwithstanding the domestic courts had examined them on their own motion (Zanola v. Italy (dec.), 2023, para. 35). Therefore, by strengthening the non-exhaustion rule, the Court is stressing the ‘subsidiary character of the machinery of protection established by the Convention in relation to the national systems safeguarding human rights’, given that the rationale ‘is to afford the Contracting States the opportunity of preventing or putting right the violations alleged against them before those allegations are submitted to the Court’ (Pindo Mulla v. Spain [GC], 2024, para. 93).

In Mansouri v. Italy the Grand Chamber went even further, since it considered that a domestic remedy can be considered effective even in the absence well-established body of domestic case-law. In the Court’s view, such absence could be explained by the fact that the remedy in question had never been used in the specific context: in a similar situation, the Court considered that it was the applicant’s duty to apply to the domestic courts, since in this way he ‘would have created an opportunity for the development of domestic case-law on this subject, and this would potentially have been beneficial to anyone else in a similar or comparable situation’ (2025, para. 99). In so doing, the Grand Chamber established a sort of presumption of the effectiveness of domestic remedies, overcoming the established principle pursuant to which ‘the availability of a remedy said to exist […] must be clearly set out and confirmed or complemented by practice or case‑law, which must in principle be well established and date back to the period before the application was lodged’ (Guðmundur Gunnarsson and Magnús Davíð Norðdahl v. Iceland, 2024, para. 44).

Recently, the Court tried to push the impact of shared responsibility on the non-exhaustion rule even further. In particular, the case of Tsaava and Others v. Georgia concerned allegations of excessive use of force by the police, and the absence of an effective investigation. In 2024 a Chamber found that the ongoing investigation had fallen short of the requirement of effectiveness within the meaning of the procedural aspect of Article 3 (para. 227) but, when dealing with the applicants’ complaint under the substantive aspect of this provision, considered that ‘more factual elements have to be elucidated at domestic level’, given that the Court ‘must be cautious in taking on the role of a first-instance tribunal of fact’ (para. 242). Accordingly, the Chamber emphasised that the investigation was still pending and observed that its capacity to assess the circumstances of the case had not been ‘irretrievably undermined’ (para. 243). It therefore considered not to be called to decide on the merits of the complaint, since ‘in line with the spirit of shared responsibility on the part of States and the Court […], it will firstly be for the domestic authorities to reach appropriate conclusions’ (para. 244). Further ‘emphasising the importance of the principles of subsidiarity and shared responsibility’, the Chamber decided to refrain from taking a decision, given that ‘such an exercise would duplicate the ongoing proceedings at domestic level, which are better placed and equipped to accomplish this task’ (paras. 245-246). As argued by Judge Gnatovskyy in his dissenting opinion, this approach is at odds with the Court’s existing approach concerning the assessment of the effectiveness of a domestic investigation for the purpose of the non-exhaustion rule, given that the Court considered the complaint to be ‘somehow’ premature notwithstanding the remedy had been declared ineffective. On this basis, the case was referred to the Grand Chamber on 24 September 2024, which held a public hearing on 26 February 2025 and will soon deliver a ruling which is expected to clarify the said issues.

In any case, the notion of shared responsibility has also affected another fundamental aspect of the Court’s activity, notably the scope and intensity of the review that it undertakes in order to rule on the question whether the domestic authorities complied with their obligations. In the past, the Court used to review the reasons given by the domestic authorities in order to justify an interference, and to balance those reasons against each other (see, as a notable example, Khurshid Mustafa and Tarzibachi v. Sweden, 2008, paras. 43-50). By contrast, in what has been defined the ‘age of subsidiarity’ (Spano, 2014), the Court progressively ‘moved away from open balancing’ (Gerards, 2023), took a ‘procedural turn’ (Arnardóttir, 2017) and developed so-called ‘process-based review’ (Spano, 2018). In particular, the Court ‘gradually developed […] supervisory mechanisms which are intended to comply fully with the principle of subsidiarity’, according to which ‘its task is to verify whether the national courts applied the principles of the Convention as interpreted in the light of its case-law in a satisfactory manner, in such a way that their decisions are consistent with it’ (Halet v. Luxembourg [GC], 2023, para. 160). This means that the Court does not focus on the reasons adduced and the outcome of the balancing between them, but rather on the quality of the decision-making process. Although this approach is not unproblematic, since, as it had been observed, ‘great injustice has been perpetrated throughout human history on the basis of seemingly correct procedures’ (H.F. and Others v. France [GC], 2022, Concurring opinion of Judges Pavli and Schembri Orland, para. 2), it remains that the Court recent practice focuses much more on the procedure than the substance of domestic decision-making processes.

Lastly, the notion in question was resorted to in order to further shape the practical functioning of the pilot judgment procedure, by prioritising the need to refer back to the domestic authorities repetitive cases in respect of which the Court has already established the relevant principles (Burmych and Others v. Ukraine [GC] (strike out), 2017, paras. 155-156).

‘Shared Responsibility’ as Imposing a Higher Standard of Diligence on the Domestic Authorities

The above process of retreat, however, cannot properly function without the implementation of the other side of the notion of shared responsibility, notably the need for a more proactive role on the part of the domestic authorities. In particular, already in 2010 Judges Spielmann and Malinverni, in their Partly dissenting opinion in the case of Maksimov v. Russia (para. 3), noted the potentially revolutionary effects of this notion, and advanced the idea that it should be used to ‘force’ Member States to ensure that the Convention is effectively incorporated in the domestic courts’ application of the law.

In the subsequent years, the notion was indeed used to overcome the previously established approach pursuant to which the Convention could not impose obligations on the domestic authorities as to the way in which they interpret and apply domestic law. In the past, it had been consistently reiterated that ‘it is not the Court’s function to express an opinion on the interpretation of domestic law, which is primarily for the national courts to interpret’ (Lambert v. France, 1998, para. 37), ‘the Court’s role being confined to determining whether the effects of that interpretation are compatible with the Convention’ (Gorzelik and Others v. Poland [GC], 2004, para. 100). By contrast, the Court recently held for the first time that ‘the principle of subsidiarity imposes a shared responsibility between the States Parties and the Court, and that national authorities and courts must interpret and apply the domestic law in a manner that gives full effect to the Convention’ (Guðmundur Andri Ástráðsson v. Iceland [GC], 2020, § 250; see also Mukhin v. Russia, 2021, para. 139 Grzęda v. Poland [GC], 2022, para. 324). Even more clearly, the Court stipulated that the subsidiary role of the Convention mechanism ‘puts the national authorities and courts under an obligation to interpret and apply domestic law in a manner that gives full effect to the Convention’ (Nalbant and Others v. Turkey, 2022, para. 46, emphasis added) and that, ‘[a]s a corollary to the subsidiarity principle, where an applicant’s pleas relate to the “rights and freedoms” guaranteed by the Convention, the courts are required to examine them with particular rigour and care’ (ibid., emphasis added; for an early reference to this obligation, Wagner and J.M.W.L. v. Luxembourg, 2007, para. 96). The Court drew relevant and appropriate consequences from this newly established obligation.

First, it found breaches of the Convention where the domestic courts had failed to rigorously and carefully assess a Convention-complaint (Nalbant and Others v. Turkey, 2022, paras. 46-47; Fabris v. France [GC], 2013, paras. 72-75; see also the cases cited in Halet v. Luxembourg [GC], 2023, para. 161), considering that this entailed a serious breach of the obligation to provide reasons justifying the impugned measure (Zayidov v. Azerbaijan (No. 2), 2022, para. 98). By contrast, the Court was satisfied that the Convention had been complied with where the domestic courts applied a domestic provision which was in principle incompatible with it – a statutory blanket voting ban – in a Convention-compliant manner – on the basis of a proportionality assessment (Kalda v. Estonia (No. 2), 2022, para. 52; but see the Dissenting opinion of Judge Serghides, para. 19, who argued that the notion of shared responsibility should not be used to ‘encourage an approach that employs an arbitrary and even contra legem application of the national legislation’).

Secondly, the said obligation was used to overcome, without formally overruling it, the principle according to which the Convention does not oblige States Parties to provide access to a remedy through which individuals can complain of the incompatibility between domestic law and the Convention (Ostrovar v. Moldova, 2005, para. 113; I.G. and Others v. Slovakia, 2012, para. 156). And indeed, the Court restricted the discretion normally exercised in many countries by the domestic courts in dealing with issues of constitutionality raised by the parties: in particular, it relied on the obligation stated above in order to find breaches of Article 6 when the domestic courts had not given sufficient reasons to dismiss a request for referral to a Constitutional Court of an issue concerning the compatibility of a domestic legislation with the Convention (Xero Flor w Polsce sp z.o.o. v. Poland, 2021, para. 171).

Thirdly, the Court clarified that, in order for it to show deference to the domestic authorities on the basis of the abovementioned process-based review, it must be satisfied that the domestic authorities diligently took into account its case-law. In this respect, the Court held that ‘it has an increased expectation that the national courts will take account of its case-law in reaching their decisions where, on the questions at issue, that case-law is both substantial and stable and where it has identified a series of objective principles and criteria that can be easily applied’ and that ‘where […] the domestic courts have carefully examined the facts, applied the relevant human-rights standards consistently with the Convention and its case-law, and adequately balanced the individual interests against the public interest in a case, the Court would require strong reasons to substitute its view for that of the domestic courts’ (Halet v. Luxembourg [GC], 2023, para. 161, emphasis added).

Lastly, the notion of shared responsibility was used in the context of the determination of the measures aimed at remedying breaches of the Convention. In this regard, the Court held that on that basis the national authorities are expected to draw fair-mindedly the conclusions that follow from a unilateral declaration by the Government acknowledging a violation and giving rise to a decision of the Court taking note of it (Boutaffala v. Belgium, 2022, para. 51) and that, as regards the implementation of judgments, it ‘imposes an obligation on the domestic courts to ensure, in conformity with their constitutional order and having regard to the principle of legal certainty, the full effect of the Convention standards, as interpreted by the Court’ (Fabris v. France [GC], 2013, para. 75).

Conclusions: A Synergic Cooperation towards a Common Aim

The analysis of the case-law incorporating the principle of shared responsibility shows that this notion has not been conceived as a mere synonym for, or restatement of, the principle of subsidiarity. Rather, it triggered more radical case-law developments which might entail, in the short and long term, a Copernican revolution for the relationship between the ECtHR and the domestic authorities.

As traditionally formulated, the principle of subsidiarity conveyed the image of some sort of distance and separation between the domestic authorities and the Court: while the latter were required to exercise their own competences, ‘[t]he Court’s task, in exercising its supervisory jurisdiction, [was] […] to review […] the decisions they delivered pursuant to their power of appreciation’ (Observer and Guardian v. the United Kingdom [Plenary], 1991, para. 59). This gave the impression that the domestic authorities were working in isolation from the Convention system, carrying out their functions, while the Court supervised them from far away, ready to point out their mistakes.

By contrast, the notion of shared responsibility was introduced not only with the purpose of finding a proper balance, but together with the concepts of interaction and dialogue. It was conceived as something capable of breaking the walls of divide conveyed by the previous understanding of subsidiarity, since it brings the image of a synergic and coordinated system, in which all actors involved work at the same time towards the same aim.

A similar image was brilliantly evoked by the Italian Constitutional Court in its recent judgment no. 33 of 21 March 2025, where it advocated for the possibility for domestic courts to interpret the Convention in a more progressive way than the Strasbourg judges. In particular, the Constitutional Court held that the new understanding of subsidiarity entails the possibility for the domestic courts of a combined interpretation of the domestic Constitution and the Convention, and that, ‘in interpreting in an integrated manner the Convention safeguards and the corresponding constitutional provisions, this [Constitutional] Court can contribute to the definition of the European protection standards’.

At the same time, the expression shared responsibility entails that the above process cannot be unilateral: the Court should not adopt a self-restrained approach if it is not convinced that, on the other side, the domestic authorities are taking their part of responsibility. In this regard, the developments described above make clear that, now more than even, ‘the whole structure of the Convention rests on the general assumption that public authorities in the member States act in good faith’ (Khodorkovskiy v. Russia, 2011, para. 255). However, in an era in which ‘Europe faces a perfect storm’ which ‘threatens to undo the peace, stability and hard-won progress the Council of Europe has helped deliver across an entire continent over the past 75 years’ (see the Introduction to the 2025 Report of the Secretary General), and with political attacks against the Court’s independence (see, Ní Chinnéide and Sevrin, on the letter published on 22 May 2025 by nine States Parties criticising the Court’s case-law in migration issues), the Court should send a clearer message that the system is not based on blind trust towards the domestic authorities, but on the trust that they must earn by proving to be good faith enforcers of the Convention. If Member States want a ‘more subsidiary’ Court, the must prove themselves ‘more proactive’.