Legal Case Summary
Flaminio Costa v ENEL (1964) Case 6/64
Established the supremacy of European Community laws over the national laws of Member States.
Facts
The claimant, Costa, was an Italian citizen with shares in the Italian electricity supply company Edisonvolta, and he sought to oppose moves by the State to nationalise the electric industry. Thus, he attempted to assert that the creditor for his electric bill remained Edisonvolta rather than the new national company, ENEL. Costa subsequently submitted that nationalisation was in violation of the Treaty of Rome. The Italian Constitutional Court viewed that the traditional rules of statutory interpretation, lex posterior derogat legi anteriori/ priori ought apply, whereby in the event of statutory incompatibilities, the newer law prevails, meaning the more recent Italian nationalisation statute would prevail over the earlier Treaty of Rome.
Issues
Should EC law, specifically the Treaty of Rome, be considered dominant over national statutes?
Decision/Outcome
The European Court of Justice overturned the verdict of the Italian Constitutional Court, finding that the Treaty of Rome’s provision regarding the single market did not have direct effect and subsequently was one that only the EC could bring a charge against a Member State for violating. However, the claimant was entitled to avail himself of the national Courts system in Italy, and attempt to contend that a national statute was not compatible with EC law, which the national Courts were thus entitled to decide. It can subsequently be found that Courts are obligated to hear and refer cases until they reach the furthest domestic appeal level where such cases concern EU law.
Updated 19 March 2026
This article remains historically accurate as a summary of Flaminio Costa v ENEL (Case 6/64) [1964] ECR 585, which established the foundational principle of the supremacy of Community law over conflicting national law. However, readers should be aware of several important points.
First, there is a notable inaccuracy in the article’s description of the outcome. The ECJ did not simply find that the relevant Treaty provisions lacked direct effect and leave the matter there. More significantly, the Court established the doctrine of supremacy of EC law, holding that Member States had permanently limited their sovereign rights by acceding to the Treaty and that Community law could not be overridden by domestic legislation. The article understates this central holding and may mislead readers about the case’s true importance.
Second, following the United Kingdom’s withdrawal from the European Union, the doctrine of EU supremacy no longer applies in UK domestic law. The European Union (Withdrawal) Act 2018 ended the supremacy of EU law in the UK from IP completion day (31 December 2020). Retained EU law was given a different status, and the Retained EU Law (Revocation and Reform) Act 2023 has further altered the position regarding retained EU law in Great Britain. This case therefore now has historical and comparative significance for UK students rather than direct domestic legal effect.
Third, the article’s statement that Courts are obligated to refer cases to the Court of Justice at the final domestic appeal level reflects Article 267 TFEU (formerly Article 177 EEC), which remains accurate for EU Member States but no longer applies to UK courts following Brexit. UK courts may in certain circumstances have regard to EU case law but are no longer bound to follow or refer to the Court of Justice.
Students studying EU law in the context of EU Member States will find the core principle described in this article still good law within the EU. UK students should treat it as a foundational case in EU law history with no continuing direct domestic application.
