The Government’s controversial plan to extend the pre-charge detention limit from 28 days to 42 was heavily defeated in the Lords tonight.

The peers overwhelmingly rejected the proposed legislation by 309 votes to 118 after it had scraped through the House of Commons in June.

The humiliating defeat for the Government came in spite of Gordon Brown’s last-ditch appeal for cross-party support this morning. "I believe the House of Lords should take the advice of the Commons," he said, but his appeals were in vain.

Even stalwart Labour loyalists such as Lord Falconer of Thoroton, the former Lord Chancellor, rejected the proposal. “If I thought that this provision for 42 days would make any difference at all in the fight against terrorism I would unhesitatingly support it,” he said, adding before the division that he would vote against the Government with a “very, very heavy heart”.

Lord Tebbit, the former Cabinet minister, was one of the few peers willing to support Home Secretary Jacqui Smith’s bill.

The former Conservative frontbencher, who was seriously injured and whose wife was permanently disabled in the IRA’s bombing of the Grand Hotel in Brighton during the 1984 Conservative Party conference, said his own party might “come to rue this day” if the Government lost the vote on 42 days.

“Think of the dilemma if the Government is denied these powers, but at some time in the future a Conservative administration concludes that it needs them,” he said.

“How exactly would they go about coming back to Parliament and asking Parliament to grant those powers. Most of my (political) friends supported indefinite detention without trial in Northern Ireland, so clearly the matter of 42 days is not an absolute matter of conscience for them.”

Tonight’s vote may spell the end for the bill with little political appetite for a battle between the Lords and the Commons. Labour ministers are believed to harbour doubts as to whether - in the event of a standoff with peers - they would have the support of dissenting backbenchers to use the Parliament Act to steamroll the measure on to the statute books.

It emerged today that 42 renowned British writers have added their voices to those attacking the plans, claiming they impinge on civil liberties. Those participating in the campaign - organised by human rights group Liberty - include Philip Pullman, Monica Ali, Julian Barnes, Ian Rankin, Alain de Botton, Ali Smith and Al Kennedy.

David Davis, the former Shadow Home Secretary who resigned to campaign against what he said was a threat to civil liberties, yesterday raised the temperature by telling the BBC's Andrew Marr Show that the plans were already dead in the water - a claim the Home Office fiercely denied.

"I think it will be dead. It was something that was profitable for the Government - they thought by having 42 days and us opposing it they would make us look weak and them look strong," he said.

"That was when 70 per cent (of the public) supported it - now it’s about 30 per cent supporting the Government. Their own party probably won’t support them in the Parliament Act, so I think it’s probably over."

David Winnick, a Labour backbencher, warned that Mr Brown was risking creating more divisions in his party by "foolishly" pushing ahead with the plan.

"It would be far better for the Government to accept the inevitable as far as the Lords is concerned and not force a very heavy defeat," Mr Winnick, who led the Commons rebellion against the plans from the Labour benches, said.

"At a time of such economic difficulties and global market crisis, what sense is there to do this when we want the Government and party to be united?"

The Home Office, however, insisted that it was determined to give police the "powers they need to tackle terrorism".

The Metropolitan Police, under the leadership of former Commissioner Sir Ian Blair, is known to support an extension, arguing that the complexity of terrorism investigations means police have to be given more time to put together their case before issuing a charge. Senior judicial figures, however, have disagreed.

"It is not true that the Counter Terrorism Bill is to be dropped," a spokesman said. "The Government is determined to give the police the powers they need to tackle terrorism.

"That is why it is right and proper to legislate now to put in place the reserve power to go beyond 28 days if in future there is a clear operational need for it.”

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