Time was when the Conservatives never had to strain a muscle, not more than the curl of a lip at any rate, to win the debate on law and order in Britain. Then came Tony Blair, tough on crime and tough on the causes of crime, and a procession of home secretaries so illiberal they could outflank the Tories from the right. David Cameron, the party's new young leader, seems to have stopped that rout, and in a way that was not wholly predictable.

His speech yesterday calling for a British Bill of Rights is an astute attempt to capture the debate on where to strike the balance between civil liberties and public security in the age of hyper-terrorism. Whether this political initiative has any useful constitutional substance will have to await a lot of further clarification.