Ministers are rethinking controversial plans to create a new offence of “glorifying” terrorism amid concern that the proposal will need to be more tightly defined if it is to work in law.

Tony Blair said on Thursday there was a balance to be struck between protecting people’s lives and putting civil liberties at risk. Asked about the new offence, the prime minister said it was important to get the wording of a bill to be published shortly “very clear and very right”.