Clare Short has signalled support for the government's strategy to rid Iraq of its weapons of mass destruction.

The international development secretary also denied charges that the government had made no plans for a humanitarian crisis following war in Iraq.

Speaking in the Commons, she insisted that aid agencies would be ready if Saddam had to be disarmed by force.

The United Nations was preparing contingencies, she said, despite leaks suggesting that their timescales were a long way behind American military capabilities being assembled in the Gulf.

"There is contingency planning taking place and we are taking full account of the risks. But humanitarians alone cannot prepare; there has to be co-operation between those who are making military plans and humanitarians."

Short also indicated her support for the government's hardline stance on Iraq.

The minister said the argument from UN inspector Hans Blix for more time was "overwhelming" but the last round of attempts to resolve the issue had been foiled by Iraq's regime.

"Saddam Hussein made it impossible for the inspectors to do their job to disarm the weapons that were there. We cannot let that happen again.

"He's impoverished his country, he's terrorised his people, he's destroyed a wealthy economy because he's so dedicated to having these weapons," Short told MPs.

"We have to find the best possible way of working through the UN and minimise the risk of military action, if it has to take place to back up the authority of the UN, of harm to the people of Iraq."

The Conservatives had accused the government of being unprepared for a refugee crisis sparked by an invasion of Iraq.

The party's international aid spokesman, Caroline Spelman, used a Commons debate to claim that no allowance has been made for humanitarian aid.

Britain will be forced to accept thousands of Iraqi refugees following a war, she said, because ministers are "in denial" about the likely impact of a war.

Contingency funding has not yet been made available and there have been no discussions with countries bordering Iraq, where borders are mined, electrified or shut, she alleged.

Spelman warned that Iran was expecting to be "deluged" with the arrival of up to a million refugees.

She cited a widely leaked UN report predicting that more than three million people will be in desperate need of food.

And she predicted that as many as 900,000 refugees will flee Iraq in the event of war.