Abstract
The Court of Justice of the European Union has, by its Opinion 2/13, postponed sine die the accession of the Union to the ECHR. However, the question of the distribution of responsibility between the Union and its member states for the protection of fundamental rights remains relevant. In fact, despite its specificity, the European Union is indeed an intergovernmental organization that depends fundamentally on its member states in its existence as in its functioning. As the latter were all parties to the ECHR, the ECtHR was called upon to rule on the possible responsibility of the Member States for human rights violations occurring within the scope of Union law. The Court, in its case law regarding international organizations in general and to the Union in particular, developed a set of liability rules for their member states. Nevertheless, it seems essential to indicate their foundations and their characteristics in order to propose a complete and coherent liability system for the member states of the European Union, able to adapt to the latter's accession to the ECHR.