After a historic day of political debate, Tony Blair won parliament's backing for military action against Iraq.

Having staked his political future on the vote, the prime minister still saw more than a third of Labour MPs rebel against his stance.

The Commons voted by 396 votes to 217, a government majority of 179, to reject a rebel amendment that would have given Iraq more time to meet its disarmament obligations.

"The House of Commons has spoken," said the prime minister's official spokesman. "Parliament is voting to support the government in its efforts to disarm Saddam Hussein."

Earlier, Tony Blair received a major boost when Clare Short announced that she was going to remain in his cabinet.

Despite telling BBC Radio last week that she would "absolutely" resign in protest at military action without a second United Nations resolution, the international development secretary performed an extraordinary u-turn and said it would now be "cowardly" to leave the government.

Short's decision to stay somewhat nullified the resignations of two ministers, John Denham and Lord Hunt.

The prime minister will be heartened to see that public opinion is beginning to swing his way.

A YouGov poll for today's Telegraph found that 50 per cent of British voters support military action, with 42 per cent still opposing an attack on Iraq.