What has been announced? David Cameron proposed a “United Kingdom sovereignty bill”, which he said would ensure the ultimate sovereignty of the British parliament. The aim is to prevent the “drift” of power from Britain to Brussels.

What does Mr Cameron say? Britain does not have a written constitution, so its legal defences against future transfers of sovereignty to the European Union are weak. He wants to make it clear that Westminster “cannot be overruled by the EU against its will”. He says the model for this is the German constitutional court, which he claims provides an ultimate safeguard “against any attempts by EU judges to erode our sovereignty”. Britain’s new Supreme Court would oversee this sovereignty act but it would not be allowed to strike down individual items of EU legislation. The Tories also admit sotto voce that the Surpreme Court would not be superior to the European Court of Justice in Luxembourg, which is charged with interpreting EU law.