Factortame was a shipping company whose shareholders were mainly Spanish, which made it subject to certain restrictions under the British parliament’s Merchant Shipping Act 1988. Factortame argued that this was contrary to EC law and therefore that the HL ought to order an injunction removing all obstructions to them caused by the Act. HL referred to ECJ the question of whether interim relief was required as a matter of EC law. ECJ ruled that a national court has a duty to grant interim relief in order to safeguard rights granted under EC law and, where a national law or procedural rule (as here) fails to observe rights granted under EC law, the courts have a duty to apply EC law and disregard the conflicting national law(s). This meant that the HL would have to (and did) grant an injunction preventing the minister from obeying parliament which contradicted the rule against issuing injunctions against the crown. This appears to prioritise effectiveness over national procedural autonomy.
ECJ: It is for the national courts, under art. 5 EC, to ensure legal protection which people derive from EC provisions with direct effect. However any provision of a national legal system, national legislation or judicial or administrative practice that prevent EC law from becoming fully effective is incompatible with the requirement for effectiveness of EC law. This is as true of a ban on interim relief as any other provision.