Amid growing indications that the government will struggle to get its new anti-terror laws through parliament, Tony Blair has said he will look for ways to co-operate with opposition parties.

The prime minister pledged to hold talks with Michael Howard following a Conservative commitment to join the Liberal Democrats in opposing the current proposals when they are debated in parliament.

With the plans facing criticism from both main opposition parties, ministers will struggle to get the proposals through the House of Lords.

Despite a muted initial reaction, opposition to the home secretary's proposals has been steadily increasing.

While the current rules have been struck down by the law lords, Charles Clarke's alternative plans for extended surveillance and house arrest are facing further opposition.

The current proposals for "control orders" also include restrictions on movement and limiting access to communications technology.

Strong defence

Speaking in the Commons, the prime minister mounted a strong defence of the need to curtail civil liberties to in order to protect public safety.

"The one thing I will not do as prime minister is engage in anything that puts the security of our country at risk," Blair told MPs. "That is absolutely paramount for me."

However, he said that he would "look at proposals from any quarter" for ways in which the current plans could be modified.

He said government wanted a judicial process to oversee the detention powers,  but said there would be a "difficulty" over any plan to allow the use of intercept evidence.

Blair added that "any such powers should only be undertaken with the greatest of hesitation".

But "nothing must stand in the way of protecting the security of our people", he said.

Growing opposition

A consensus is emerging between the two main opposition parties that would reject the introduction of the home curfew proposals.

The government could also be forced to accept greater judicial oversight of other measures such as surveillance and electronic tagging.

Howard accepted the need to protect the public from terrorist attack, but said that the government should not "lose sight of the need to protect our way of life".

He said there should be a cross-party approach to the issue, and urged the prime minister to hold talks with his party.

At an earlier press conference, the Tory chief said his party had "thought long and hard about these proposals" before making its final decision.

"We have serious misgivings about both their effectiveness in protecting life and their consequences for the British way of life," said Howard.

"The government believes that it is acceptable for suspected terrorists – whether British citizens or foreigners – to be put under house arrest by order of the home secretary.

"I do not believe that anyone should be deprived of their liberty on the say so of a politician.

"The government believes in house arrest.  I do not. If people are dangerous terrorists, they should be in prison, not at home.

"I am also concerned that house arrest could well be counter productive."

Lib Dem home affairs spokesman Mark Oaten also said the proposals would "make a bad situation worse".

"We have come to the conclusion that when you have to balance on the one hand the civil liberty issues and on the other the security of the nation, we believe that the government firstly got it wrong by holding detainees in Belmarsh, but they are now making a bad situation worse by suggesting house detention and control orders," he told the BBC.

Conservative proposals

Howard said that those accused of terrorist offences should be brought to trial instead of facing continued detention.

"While they await trial, they must be detained in prison," he said. "Their innocence or guilt must be determined by a court of law – not by the home secretary.

"If they are found guilty, they must be detained in a prison cell, not in their living rooms. That is the way to protect life and to protect the British way of life."

He added that phone-tap evidence should be admissible in court.

"I hope that the prime minister will look carefully at our proposals, just as we have looked carefully at his," added Howard.

"I want to enter into constructive discussions with the government to see if we could agree on a better way forward.

"If we can, the Conservative Party will co-operate to get the necessary emergency legislation through parliament as quickly as possible."

Lib Dem plans

Liberal Democrat leader Charles Kennedy told MPs that a new offence of "planning terrorism" should be created in order to protect people's civil liberties.

"Can I say that we would all accept that it's the fundamental duty of the government to protect its citizens," he said.

"The issue [is that] in so protecting its citizens it also upholds their fundamental civil rights.

"The way forward should be for the government to create a new offence of planning acts of terrorism, then the issue of any control orders should be issued by judges not politicians, should be time limited and it should require the highest possible burden of proof."

Oaten added that the emphasis should be on prosecuting suspects in the courts.

Wire tap evidence should be made available and "we think there could be a role for some form of control order, tagging, surveillance, limitation on the use of mobile phones", he said.

"But not with the home secretary's say-so. That must be done through a proper judicial process, a judge involved in making those decisions."