Britain published sweeping plans to fight terrorism yesterday which, if passed into law, would let police hold suspects for three months without charge, sparking anger from senior judges and civil rights groups.

However Tony Blair's government may still have to back down on the most contested parts of the Bill, which was drawn up after four British Islamist militants blew up 52 commuters and themselves on London's transport system in July.

The government has heeded police calls to extend the time they can detain terrorism suspects without charge to 90 days from 14. Police say they need longer to sift through evidence, including computer records, if they are to prevent attacks.

"I have found their request absolutely compelling," Mr Blair told Parliament. "I have to do my best to protect the people of this country and to make sure their safety... comes first."

Critics say the measures are draconian compared with other countries and even Britain's top judge has attacked the plans.

"Occasionally one feels that an individual politician is trying to browbeat the judiciary, and that is wholly inappropriate," said Lord Phillips.

The government-appointed reviewer of security legislation, senior lawyer Lord Carlile, also expressed reservations.

"If there are to be extensions for up to three months... in my view the protections (for the suspect) built into the Bill as drafted are inadequate," he said.

Britain says its plans are not extreme, but comparisons with other states are problematic due to differing legal systems.

Terrorism suspects in France and Spain can be held for questioning - a process which in Britain has to stop when a suspect is charged - for years. However, a judge, not the police, controls the process.

Mr Blair's centre-left government, which wants a cross-party consensus to push the measures through Parliament, may be forced to make concessions on some of the most contested points.

"I think they are in serious trouble," said opposition Liberal Democrat Mark Oaten.

"I believe LibDem, Conservative and many backbench Labour (lawmakers) feel very strongly that holding individuals without charge for 90 days breaks too many long-held principles."

The Bill will be a test of Mr Blair's authority over his party.

His Parliamentary majority was more than halved in May's election and he has already risked seeing his power gradually diminish by declaring he will stand down in the next few years.

Without cross-party support, the Bill would fail if only about 35 Labour members vote against it in coming months.

The law would also outlaw the encouragement or glorification of terrorism and the giving or receiving of terrorist training.

Lawyers and campaigners say the measures pose definition problems and risk damaging relations between the police and Britain's Muslim community at a critical time.

They also criticise steps taken to ban or deport radical Islamist clerics which they say could contravene the European Convention on Human Rights.