6/64 Falminio Costa v ENEL  ECR 585
EUROPEAN UNION – DOCTRINE OF SUPREMACY – CONFLICT OF LAWS – EEC TREATY AND ITALIAN MUNICIPAL LAW
In 1962 the Italian Republic introduced a law which nationalised the production and *427 distribution of electricity and created an organisation, ENEL, to which was transferred the property of the electricity undertakings.
The applicant was a shareholder of a firm which had been affected by the nationalisation, and claimed that he was not liable for a bill sent to him for electricity supplied to him by ENEL. In proceedings before the Giudice Conciliatore (Justice of the Peace) of Milan, C claimed that the Nationalisation Law of 6 December 1962 was contrary both to the Italian Constitution and to a number of provisions of the E.E.C. Treaty.
The European Court of Justice were required to adjudicate upon the doctrine of supremacy as it pertained to the relationship between domestic and Community law, namely whether Community law and the provisions of the various treaties limited the ability of Member States to enact legislation which ran contrary to those provisions.
An Italian law, enacted to bring into effect an international treaty, is no different from any other law, and is subject to the normal rules with respect to implied repeal when it conflicts with other laws. The violation of a treaty provision does not invalidate a domestic law. However, as the Treaty of Rome involved the partial transfer of sovereignty from Member States to the Community itself, a subsequent unilateral law which is incompatible with the aims of the Community could not prevail.