By Nick Assinder
Political Correspondent, BBC News website
The government's controversial anti-terror laws may have scraped through the Commons after a major last-minute concession, but things are now set to get rougher in the House of Lords.
Home Secretary Charles Clarke has insisted he is not ready to make any further concessions, declaring the Bill should now attract Peers' support.
Clarke's Bill will run into Lords trouble
But there are plenty of signs his optimism will prove unfounded and that he may indeed be forced into accepting further changes.
The Conservative leader in the House of Lords, Lord Strathclyde, has warned the changes announced by Mr Clarke in the Commons, but to be tabled in the Lords, did not go far enough.
"I think the Government should prepare themselves for substantial rewriting of various aspects of the Bill," he said.
The areas under attack are the government's refusal to allow the use of phone taps and other intercept evidence against terror suspects, and the "most objectionable" proposal for house arrest - the heart of the Bill.
If Mr Clarke had to give on either of those, or was defeated on them, his original Bill would be in tatters.
And there is mounting speculation in Westminster that something will indeed have to give.
Opposition to the proposals from the Conservatives and the Liberal Democrats has not been ended by the concession of giving judges first say in the most severe control order cases.
At the very least, many are demanding that should now apply to all control orders.
But there are also those wider concerns, with civil liberties groups fundamentally opposed to the very basis of the proposed legislation.
Shami Chakrabarti, director of the pressure group Liberty, has gone so far as to describe the row over judicial involvement as "a complete red herring".
Branding the legislation "odious and unpalatable" she insisted the bill was an infringement of basic liberties.
There has been a warning of a threat to the election
"What is so problematic and unfair is that a person is punished with no charges against them and certainly no knowledge of any charges or evidence or proof, no ability to test the case against them or know what it is," she said.
That is a view held by many across the political divide in both the Commons and the Lords and will almost certainly see attempts to radically re-draft the legislation in the Lords.
Mr Clarke may not want to change his Bill any further, but he may find he has no choice.
Ministers have latched onto opinion polls suggesting voters support the tough new measures to combat terrorism.
And they are confident that this will not turn into a vote loser come the general election.
Indeed there have been suggestions that both sides are playing politics with this issue - with the Tories looking for a parliamentary victory and Labour seeking to portray the opposition as soft on terror.
And what is certain is that, following the Law Lords ruling against the existing anti-terror laws, there does have to be new legislation.
But just what shape those laws will finally take is still far from certain.