The constitutional identity of the member states: False evidence or constitutive element of a new architecture of the Union?

The notion of ‘identity’ once seemed perfectly obvious and applied mainly to individuals. A spectacular evolution of the notion could have been considered in recent years. In the social sciences where it was associated with the notion of group but, after having invaded the public debate, it has now reached the law domain. It now appears in the debates and even the decisions of the constitutional courts of the member states of the European Union. This is a general movement which is part of a climate in which, to varying degrees, there is expressed dissatisfaction with regard to the operation of the institutions of the Union and, more particularly, their mode of creation of law, as soon as it benefits from the principle of primacy affirmed by the Treaties.The purpose of this article is to gather and evaluate the information available through the various case law and comments, in order to better clarify the notion of constitutional identity and assess its effectiveness. The concept remains contested, and its use has not yet resulted in significant consequences, but its study is an opportunity to suggest improvements in the dialogue between the constitutional courts and the Court of Justice of the European Union; to also ask whether the notion of ‘constitutional identity’ could not be a valuable tool in redefining the relationship between the Union and the Nations that compose it.