By Nick Assinder
Political correspondent, BBC News website
Just two years after Tony Blair suffered a serious defeat at the hands of his own backbenchers over detention without trial, Gordon Brown is trying again - so what's different now?
The prime minister told the Commons he is still seeking consensus to double the current, controversial, 28 day limit but, as Tory leader David Cameron made plain, he is not there yet.
Mr Brown's proposals are aimed at beefing up security
But, in what may just be the start of a process that will bring the Tories on-side, the prime minister announced a surprise U turn and accepted the opposition's long-held demand for a border force, which will come into effect very quickly.
And he signalled he was ready to think again over Tory calls for the use of intercept evidence, such as phone taps, in court, and to allow the post-charge questioning of terror suspects.
Much of his package of measures, designed to beef up the fight against terrorism and boost national security, will now go into a lengthy consultation period in a desire to forge that cross-party consensus.
But on the most controversial proposal to extend the period of detention, Mr Brown may still be in trouble.
If David Cameron, Sir Menzies Campbell and sceptical Labour backbenchers continue their opposition, Mr Brown faces almost certain defeat on a key proposal in the early days of his premiership. That would take some of the "bounce" out of him.
So, Mr Brown must believe he can win over his own doubters and the Tories, at least, to allow him to win the day. And, it is suspected, by accepting some previous Tory proposals, he is looking for a tit-for-tat deal.
At the moment, Mr Cameron continues to insist there is no new evidence to back an extension to the 28 days.
Mr Brown, on the other hand, is arguing that the increasing complexity of anti-terror operations makes an extension beyond that period essential to protect the public.
Mr Brown risks possible defeat
He is also determined to look tough on law and order, leaving the Tories in the potentially uncomfortable position of facing claims of being soft on the issue - something Tony Blair previously claimed.
Meanwhile, there is set to be a separate row over Mr Brown's continuing support for ID cards, something both opposition parties and many Labour MPs are also opposed to, but which have already been approved by Parliament.
Both the Tories and the Liberal Democrats, as well as a number of Labour MPs, continue to argue the system will not work and that cash could be better spent on more policing.
At the moment the Tories appear adamant in their opposition and Mr Cameron has shown little sign he is ready to change his opinion.
He will be delighted that Mr Brown has accepted his border force policy, but that will be tinged with irritation that Mr Brown has shot his fox.
He will also fear he has been wrong footed by the prime minister's apparent readiness to accept Tory ideas, in the spirit of consensus, while he has, so far, offered nothing in return.
But there is plenty of time for trimming.