Plans to allow terror suspects to be detained for up to three months without charge could yet be watered down, Home Secretary Charles Clarke has indicated.
Lib Dems are unhappy with plans to extend detention without charge
Mr Clarke said his preference would be a compromise with opposition parties concerned at the three month plans.
Writing in the New Statesman magazine he said he still believed the current time limit of 14 days should increase.
The Liberal Democrats' Mark Oaten said on Wednesday the party would not vote in favour of a 90-day detainment limit.
Mr Clarke had set out his plans detaining suspects in letters to his Tory and Liberal Democrat counterparts last week, but voiced his own doubts in a draft of the letter.
In the New Statesman article he said: "I'm convinced the three months is fine. But because David (Davis) and Mark (Oaten) had raised doubts, I was uncertain quite how to word the covering letter.
"Will we compromise? We will seek to do so. My preference is to work on a basis of compromise and agreement if we can. But if Mark Oaten wants to say there is no case for extending the time beyond 14 days, I couldn't accept that.
"But you could have a slightly different argument about timescale."
Speaking at the Lib Dem annual conference in Blackpool, Mr Oaten said plans to extend custody without charge to a maximum of 90 days and making "glorifying" terror an offence would damage civil liberties.
He said the Lib Dems would vote against these plans in Parliament - breaking the cross-party anti-terror consensus.
Ministers have said complex terror inquiries create a need for longer custody.
Mr Clarke also indicated the Government could be prepared to pull out of the European Convention on Human Rights.
He said being unable to defend Britain against a potential terrorist would put "almost unstoppable pressure" on politicians.
"People would ask whether we were really saying that adherence to the European Convention was more important than Joe Bloggs blowing up a Tube train," he said.