The doctrine of pre-emption differs from the Supremacy clause of EC law ruled in Costa v. ENEL4 in that the latter is a guide when two existing norms regulating the same thing are in conflict,5 whereas pre-emption consists in determining whether there is a conflict between a national measure, be it in application or decision, and a rule of Community law.
In a further step, in (Case 11/70) Internationale Handelsgesellschaft GmbH6, the Court held that Community law took precedence even over a fundamental rule in the German national constitution. The clearest statement of the implications of the supremacy of Community law came in (Case 106/77) Simmenthal SpA (No. 2)7 where the Court held that national courts, even a lowly court of first instance, have a duty to set aside provisions of national law, which are incompatible with EC law. There was no need to wait for the national law to be amended in line with national constitutional procedures: the national rule had to be set aside immediately if it conflicted with a directly applicable or directly effective Community provision. Nor does the obligation to set aside conflicting national rules only apply to national courts: even an administrative agency dealing with a national social insurance scheme was held to be required to do so in Case C-118/00 Larsy v INASTI8. Although the national measure is rendered 'inapplicable', this does not absolve the Member State from the need formally to repeal it.
In [Case 22-70] the ERTA case (European Road Transport Agreement) the ECJ decided that where the EC concludes a treaty in pursuance of a common policy (Transport, in this case), the possibility of concurrent authority on the part of MS towards non-member states is excluded: and any other purported exercise of concurrently authority will be over ridden to the extent that it conflicts with Community law. However, the ECJ develop pre-emption legal principle. The Court first formulated a principle of pre-emption in the ERTA case where the Court held that "once a Community common policy has been initiated,9 Community competence pre-empts Member State competence". Subsequently in Costa v. ENEL10, the principle of pre-emption has been made pragmatic and more flexible.
In the interests of legal certainty, the Court said that Member States must also repeal the offending national rule: (Case 167/73) Commission v France (French Merchant Seamen)11.
Even if it is not yet clear whether a person actually has a right which they claim under community law (i.e. it is a 'putative' right, not a definite one), the doctrine of supremacy requires a national court to set aside any national procedural rules which might prevent them from getting the full benefit of the Community right if it IS eventually found that they have it!
This was laid down in the case (C-213/89) R v Secretary of State for Transport, ex parte Factortame Ltd and others12. Spanish fishermen claimed that the UK's Merchant Shipping Act breached a number of EC Treaty articles and wrongly prevented them from fishing in British waters. They asked for interim relief (an injunction setting aside the offending clauses of the Act pending the full hearing of the case). The problem was that under English law, courts could not