Perhaps we should call it a 42-days wonder. David Davis’s decision to resign his Westminster seat and trigger a by-election over the government’s terror detention plan certainly commanded attention on Thursday. The move by the shadow home secretary may even keep the issue in the public eye for the weeks of the local campaign. But it is unlikely to leave any permanent mark, and it makes it harder to present the Tories as a party that is serious about taking power.

Mr Davis said on Thursday that he was resigning to take a stand against the erosion of civil liberties in the UK. His move follows the government’s success in forcing through the House of Commons its plans to extend the time that terrorist suspects can be held without charge. It is clear he also has in his sights the prospect of a national identity card scheme and the widespread use of CCTV cameras.