An emergency meeting of Tony Blair's cabinet is to be held shortly as the build-up to apparent war with Iraq intensifies.
Blair faces possible cabinet resignations
As ministers made their way to Downing Street, the British ambassador to the UN, Sir Jeremy Greenstock, ruled out a further resolution and appeared to put blame on France.
The prime minister knows he faces growing opposition from his own MPs and possible cabinet resignations if the course to war proceeds without further UN backing.
Clare Short and Robin Cook are seen as the most likely to go.
They seem unlikely to be swayed by the Attorney General, Lord Goldsmith saying legal authority for war came from three previous UN resolutions.
Downing Street said that Foreign Secretary Jack Straw is likely to make a statement to MPs regarding the Iraq crisis at 1900 GMT.
Ministers are discussing holding a new vote in Parliament on the Iraq crisis on Tuesday.
Fears that war is imminent heightened when the Foreign Office advised all Britons in Kuwait, except diplomatic staff, to leave the country.
Mr Blair will report to the cabinet developments from Sunday's emergency summit in the Azores with US President George Bush and Spanish Prime Minister Jose Maria Aznar.
The prime minister's spokesman signalled there would not be a vote on a second resolution, declaring: "The central issue here is whether, in what is obviously a diplomatic crisis of very serious proportions, there is anything approaching a consensus that could be discussed."
In an effort to win over sceptics ministers are repeating assurances about the security of Iraq's oil reserves and efforts to resolve the Palestinian crisis.
Speaking while returning from the summit, Mr Blair said the UN had to decide overnight on a fresh resolution with "teeth".
Earlier, at a news conference after the Azores meeting, Mr Bush repeated Monday was the deadline for diplomacy on Iraq and a "moment of truth" for the world.
He said the UN Security Council had a final day to issue the Iraqi president with an ultimatum if he continued to defy the world.
On Monday, Foreign Office Minister Mike O'Brien accused France of frustrating the diplomatic process with its veto threat.
But there was still time for French President Jacques Chirac to show "statesmanship" and change course, he argued.
Those comments sparked some concern among Labour and Lib Dem MPs who believe diplomatic efforts should continue.
If Mr Blair goes ahead with a Commons debate on military action, MPs warn they will table an amendment stating there is no moral justification for war without a new resolution.
More MPs than the 122 who voted against the government last time are expected to rebel this time.
Ex-Labour whip Graham Allen and a group of MPs, including former cabinet minister Chris Smith, are drawing up the amendment.
It would make clear their support for British troops but challenge the "moral authority" of war.
The Conservative Party has remained steadfast in its support for Mr Blair.
But Liberal Democrat leader Charles Kennedy told his party conference on Sunday: "If the president and the prime minister were serious about finding a peaceful solution, they'd be talking to Kofi Annan, not to each other."
The Stop The War Coalition is this Saturday set to organise a repeat of the peace rally which last month attracted between 750,000 and 2m people in London.