Amministrazione delle Finanze dello Stato v Simmenthal SpA Case 106/77 [1978] ECR 629

Simmenthal imported beef into Italy and was charged veterinary and public health inspection fees under Italian legislation. In an earlier reference, the European Court of Justice had ruled that charges of that kind were incompatible with Community law. The Pretore di Susa ordered the Italian finance administration to repay the fees, but the administration objected. Italian constitutional practice indicated that a later national statute remained effective until the Constitutional Court declared it unconstitutional. The Pretore therefore faced a conflict between directly applicable Community rules and Italian Law No 1239 of 1970. It made a further preliminary reference asking whether it had to disregard the national legislation immediately or first seek its removal through legislative or constitutional procedures.

Must a national court give immediate effect to directly applicable Community law by disapplying conflicting national legislation, including a later statute, without awaiting repeal or a ruling from the national constitutional court?

The European Court of Justice held that every national court must apply Community law in its entirety in a case within its jurisdiction and protect the rights it confers. The court must therefore set aside any conflicting national provision, whether adopted before or after the Community rule. It need not request or await repeal by the legislature or invalidation through a constitutional process. Requiring such a prior step would temporarily deprive Community law of full and uniform effect and transfer the resolution of the conflict away from the court responsible for applying it. Supremacy rendered the conflicting national measure inapplicable for the purposes of the case; the national court was not required formally to annul the legislation.

A national court applying a directly effective rule of EU law must give that rule full effect and, where necessary, disapply of its own motion any conflicting national legislation. This duty extends to legislation enacted after the EU rule and cannot be postponed pending legislative repeal or constitutional review.

Simmenthal converted the supremacy established in Costa v ENEL into an immediate judicial obligation. Supremacy concerns priority in application: an ordinary national court disapplies the incompatible rule in the case before it rather than declaring the statute void for every purpose. The judgment informed Factortame (No 1), where effective interim protection was required despite a conflicting domestic rule. For current UK law, the general priority regime changed after withdrawal, particularly through the European Union (Withdrawal) Act 2018 and the Retained EU Law (Revocation and Reform) Act 2023; continuing effects now depend on the applicable post-Brexit legislation and withdrawal arrangements.