Costa v ENEL

Flaminio Costa v ENEL (1964) Case 6/64 was a landmark decision of the European Court of Justice which established the primacy of European Union law (then Community law) over the laws of its member states.[1]

Costa v ENEL
Decided 15 July 1964
Full case nameFlaminio Costa v E.N.E.L.
Case number6/64,
Case typeReference for a preliminary ruling
ChamberFull court
Nationality of partiesItaly
Procedural historyGiudice conciliatore di Milano, Sezione I, ordinanza del 16 January 1964 21 January 1964 (RG 1907/63)
As a subsequent unilateral measure cannot take precedence over community law, the questions put by the Giudice Conciliatore, Milan, are admissible in so far as they relate in this case to the interpretation of provisions of the EEC treaty
Court composition
Robert Lecourt
Advocate General
Maurice Lagrange


Mr. Costa was an Italian citizen who had owned shares in an electricity company, Edisonvolta, and opposed the nationalisation of the electricity sector in Italy. He asked to two lower courts in Milan (two different Giudici conciliatori) to ascertain that the real creditor of his electricity bill (a relatively small amount of money, 1,925 lire) was the nationalised company, Edisonvolta, and not the newly established state company, Enel. He argued that the nationalisation of the electricity industry violated the Treaty of Rome and the Italian Constitution. The first Giudice conciliatore of Milan referred the case to the Italian Constitutional Court and the second Giudice conciliatore referred it to the European Court of Justice.

The Italian Constitution Court gave judgement in March 1964, ruling that while the Italian Constitution allowed for the limitation of sovereignty for international organisation like the European Economic Community, it did not upset that normal rule of statutory interpretation that, where two statutes conflict, the subsequent one prevails (lex posterior derogat legi anteriori/priori). As a result the Treaty of Rome which was incorporated into Italian law in 1958 could not prevail over the electricity nationalisation law which was enacted in 1962.[2]

In light of the decision of the constitutional court, the Italian government submitted to the ECJ that the Italian court's request for a preliminary ruling from the ECJ was inadmissible on the grounds that, as the Italian court was not empowered to set aside the national law in question, a preliminary ruling would not serve any valid purpose.


The ECJ held that the Treaty of Rome rule on an undistorted market was one on which the Commission alone could challenge the Italian government. As an individual, Costa had no standing to challenge the decision, because that Treaty provision had no direct effect. However, Costa could raise a point of EC law against a national government, in legal proceeding before the courts in that member state, since EC law would not be effective, if Costa could not challenge national law on the basis of its alleged incompatibility with EC law.[3]

As opposed to other international treaties, the Treaty instituting the E.E.C. has created its own order, which was integrated with the national order of the member-States the moment the Treaty came into force; as such it is binding upon them. In fact, by creating a Community of unlimited duration, having its own institutions, its own personality and its own capacity in law, apart from having international standing and more particularly, real powers resulting from a limitation of competence or a transfer of powers from the States to the Community, the member-States, albeit within limited spheres, have restricted their sovereign rights and created a body of law applicable both to their nationals and to themselves. The reception, within the laws of each member-State, of provisions having a Community source, and more particularly of the terms and of the spirit of the Treaty, has as a corollary the impossibility, for the member-State, to give preference to a unilateral and subsequent measure against a legal order accepted by them on a basis of reciprocity.


It follows from all these observations that the law stemming from the treaty, an independent source of law, could not, because of its special and original nature, be overridden by domestic legal provisions, however framed, without being deprived of its character as community law and without the legal basis of the community itself being called into question.[4]


This groundbreaking case established the principle of supremacy in EU law, which is an independent source of law that cannot be overridden by domestic laws.[citation needed]

See also


  1. Hilf, Meinhard (2012). Costa v. ENEL case, in Wolfrum, Rudiger (ed.): The Max Planck Encyclopedia of Public International Law. Oxford: Oxford University Press, p. 824.
  2. de Witte, Bruno (2011). Craig, Paul; de Búrca, Gráinne (eds.). Direct Effect, Primacy, and the Nature of the Legal Order. The Evolution of EU Law. Oxford: Oxford University Press. p. 328. ISBN 978-0-19-959296-8.
  3. Case 6/64 Costa v ENEL [1964] ECR 595
  4. Case 6/64 Costa v ENEL [1964] ECR 593