Clare Short has warned of the potential "break up" of the authority of the United Nations if the US and its allies launch a unilateral attack on Iraq.

I will stay as long as I can to get it as right as I can

Clare Short

In an interview with BBC News 24's Hardtalk programme, to be broadcast on Wednesday, the international development secretary says the world will become even more "bitterly divided" if military action is launched without the sanction of the UN.

Her comments are in apparent contrast to the stance of Prime Minister Tony Blair, who has consistently refused to rule out unilateral action.

In his speech to the Labour conference in Blackpool, Mr Blair insisted the threat to the UN's authority would come if it failed to deal with Saddam Hussein's weapons of mass destruction.

'Readiness for war'

Mr Blair said: "If at this moment having found the collective will to recognise the danger, we lose our collective will to deal with it, then we will destroy not the authority of America or Britain but of the United Nations itself.

Straw believes the Security Council can resolve its differences

"Sometimes, and in particular dealing with a dictator, the only chance of peace is a readiness for war."

Speaking immediately after Mr Blair's speech, Ms Short said she was "completely" happy with his position on Iraq.

She told BBC News: "What the leader has put to the conference, kept us altogether around operating through the UN, so that is where we are and we believe in absolutely strengthening the authority of the UN both for this crisis and other crises that need to be settled in the world."

Resignation threat

But in her Hardtalk interview, Ms Short reveals the depth of her concern about Iraq - and refuses to rule out resigning from cabinet if the UN is over-ruled.

She said: "I think we're in a very dangerous situation for the world.

"If there was to be action without UN support we will begin to see the break up of the authority of the UN which would be very dangerous."

Asked if she would be "leaving the caravan train" if that happened, she replied: "I will stay as long as I can to get it as right as I can."

Ms Short's resignation would be a huge blow to Mr Blair, making it more difficult for him to hold together his government and the Labour Party over Iraq.

Mr Blair held a private meeting with Ms Short ahead of last week's emergency cabinet debate on Iraq in an effort to allay her concerns.

New UN resolution

The row comes as the United Nations and Iraq agree on practical arrangements for the return to Iraq of UN weapons inspectors, under existing UN resolutions.

The US has threatened to "thwart" this latest move unless conditions are tougher.

It will continue to press for a UN Security Council resolution that would specifically mention the threat of military intervention should the inspectors be unable to complete their work.

UK Foreign Secretary Jack Straw has said a new resolution is needed to give Saddam a choice between "coming quietly and having the full force of the international community, military force, against him."

Labour party delegates backed the government's stance on Iraq in a vote on Iraq on Monday.