Saddam Hussein has a last chance to opt for peace, said UK Foreign Secretary Jack Straw as he tried to fend off a potential revolt on Iraq policy.

The House of Commons will vote later on Monday evening on the latest United Nations resolution about Iraq's alleged weapons of mass destruction.

The choice for war or peace lies with Saddam

Tony Blair

Liberal Democrats, as well as some rebels on the Labour government's benches, want MPs to vote ahead of any military action against Iraq.

Mr Straw said there would be a vote ahead of a possible war as long as it did not threaten the safety of British soldiers relying on the "element of surprise".

UK ministers last week confirmed the UK was among 60 nations to have received a request from America for troops for possible action.

There has been speculation Mr Hoon could use the debate to announce that the UK is preparing to call up reservists ready for a possible war.

War vote?

Defence sources say Mr Hoon will not be drawn into numbers, or say when reservists will receive their call-up papers.

But opening the Iraq debate, Mr Straw said no statement about calling up reservists was "currently in prospect".

The last time the Commons debated Iraq policy, more than 50 Labour rebels voiced their opposition to war in a technical vote.

Blair stressed the strength of Nato's warning

On Monday, a government motion backing the latest UN resolution on Iraq is being debated.

Anti-war Labour MPs had tabled a motion calling for any military action to have the "explicit authority" of a Commons vote.

That text will not be debated but a Liberal Democrat amendment will got a vote.

Second resolution hopes

It says no military action should be taken against Iraq without a fresh mandate from the UN and a new Commons vote.

Mr Straw argued it would be "utterly irresponsible" to hold any vote which put lives at risk, with Lib Dem spokesman Michael Moore denying that was the effect of his party's calls.

The foreign secretary said the UK hoped there would be a second UN resolution before any military action, although none was necessary.

Saddam Hussein had "his final opportunity to take the pathway to peace", said Mr Straw.

Hoon has received a US request for troops

Conservative shadow foreign secretary Michael Ancram said his party backed the UN resolution and the determination to rid Iraq of weapons of mass destruction.

Mr Ancram pressed for clarity on what would constitute a breach of the resolution.

"Whatever happens the integrity and sovereignty of the state of Iraq is maintained," said Mr Ancram, echoing the UN resolution.

'Devastation' forecast

Despite Mr Straw's promise of a vote at the "appropriate time", Labour's Neil Gerrard raised fears MPs could be getting their last chance to have their say before action.

Urging people to support the Lib Dem motion, Mr Gerrard said: "I have real fears about the political consequences of any war on Iraq.

"It could have devastating consequences for the whole of the Middle East region."

Earlier, Prime Minister Tony Blair said Saddam Hussein faced the might of Nato allies if he failed to give up his alleged weapons of mass destruction.

Reporting back to the House of Commons from last week's three day Nato summit in Prague, Mr Blair also warned that the threat of terrorism was "not a war we can avoid".

Mr Blair underlined Nato's "remarkable statement of defiance" against the threat of international terrorism and weapons of mass destruction.

Mr Blair said there was no appeasing fanatics, whose enemy was "anyone who isn't them".

"The threat of weapons of mass destruction in the hands of rogue, unstable states is not part of some different danger," he said.

"It too, like terrorism, represents savage indifference to human life."