Date de parution : 27/11/2025

Résumé : The essay reconstructs the mechanism of mutual influence between European Union law and the domestic law of member States, focusing on how the disapplication of national rules operates.  This mechanism is analyzed through a comparative lens. By examining the jurisprudence of the UK Supreme Court and of the European Court of Justice, the author shows that the relation between EU law and national law does not amount to a transfer of sovereignty, but rather to a delegation of powers.  From this perspective, the essay challenges the idea of a simple “fusion” of legal systems: instead, it proposes a model of continuous interaction. National and European legal orders constantly modify one another creating an ongoing cycle – or even a form of “fission”– that produces new energy for the legal system as a whole.