TONY Blair won the backing of the Commons to send troops into Iraq after an impassioned speech in Parliament, but suffered the biggest Government rebellion in modern times.

A total of 138 Labour MPs - plus one teller - backed a rebel amendment calling for more time for weapons inspections, outstripping the 121 Labour backbenchers who voted against the Government in the last Iraq debate nearly a month ago.

But there was relief among ministers that the revolt was not worse.

British troops amassing in Kuwait were preparing for a battle which could now be just hours away. US President George W Bush has given Saddam and his two sons until 1am tomorrow to flee Iraq or face war.

The Iraqi regime flatly rejected the ultimatum, declaring that Iraq did not choose its leaders "by decree from Washington, London or Tel Aviv".

Meanwhile, Turkey's government said today it would ask parliament to grant the US Air Force the right to use Turkish airspace in an Iraq war but would not immediately ask the legislature to vote to allow in US troops, a move which would open up a northern front against Iraq.

Cabinet spokesman Cemil Cicek said a resolution allowing airspace rights would be put before parliament tomorrow and that a separate motion allowing in US troops could be considered at a later date.

It was reported that the Turkish government was going to ask parliament to allow in US troops tomorrow but Mr Cicek said this had been a misunderstanding.

"What they have requested is for transit passage (of planes) only," Mr Cicek said. "Whatever the needs will be in the coming days - that is a different matter."

He said the latest resolution would also allow Turkish troops to enter Iraq if there is a war and Washington had agreed in principle to allow Turkish troops in northern Iraq.

The number of rebels in the Commons vote last night fell short of the 165 mark which would have left the Government needing to rely on Conservative votes to go ahead with military action.

Labour MP Bob Marshall-Andrews, who voted against the Government, said the size of the rebellion meant Mr Blair did "not have a mandate to send people to war".

Graham Allen, another leading rebel, said it was "incredible" that the vote had not only held up but increased, despite two weeks of Government pressure.

"That is a long time for individuals to be subject to such sustained pressure from the full might of the Government machine," he said.