The Advocate General of the European Court of Justice (ECJ) has declared that plans to form a European Patents Court are incompatible with EU treaties, marking a setback in the long-running campaign to create a centralised patent litigation system in Europe.

The Council of the European Union requested the opinion of the ECJ last June, with the Advocate General's response on 2 July stating that: "As it stands at present, the envisaged agreement creating a unified patent litigation system is incompatible with the treaties."

The proposed system, recently renamed the European and European Union Patents Court, was put forward in an effort to centralise the patent litigation system under one court in Europe and cut down on jurisdictional issues.