Terme de Glossaire

In the Costa v ENEL ruling, the Court of Justice of the European Union established the supremacy of European Union law over the laws of its Member States.
In 1962, Italy decided to nationalise the production and distribution of electricity, by aggregating the assets of the electricity companies in the company ENEL (Ente Nazionale per l’Energia Elettrica). Flaminio Costa, a shareholder of one of the companies affected by this nationalisation, refused to pay his electricity bills. He was brought before a court in Milan and in his defence he argued that this nationalisation violated the Treaty of Rome. In its 15 July 1964 decision, the Court ruled that the law stemming from European institutions is integrated into the legal systems of the Member States and is applicable in their courts. It did not rule on the specific case of Mr Costa’s default of payment (which remained within the jurisdiction of Italian justice) but affirmed for the first time that European law prevailed over national law.