The EU's highest court has been asked to rule on the legality of a controversial anti-piracy agreement, the Anti-Counterfeiting Trade Agreement (Acta) which has been criticized by rights campaigners who argue it could stifle free expression on the internet. EU trade head Karel De Gucht said the court will be asked to clarify whether the treaty complied with "the EU's fundamental rights and freedoms".

The agreement has so far been signed by 22 EU member states. The European Commission said it on Wednesday: "decided today to ask the European Court of Justice for a legal opinion to clarify that the Acta agreement and its implementation must be fully compatible with freedom of expression and freedom of the internet".

Several key countries, including Germany and Denmark, have backed away from the treaty amid protests in several European cities.

Acta is set to be debated by the European Parliament in June.