Cabinet ministers should be touring the country to persuade the public of the case for war with Iraq, Iain Duncan Smith has said.

The Conservative Party leader repeated his commitment to the prospect of military action if Saddam Hussein fails to disarm.

I think this is a critical moment for the UN Iain Duncan Smith

But he acknowledged that many people in the UK remain unconvinced.

"I do want to see members of the Cabinet actually going round the country now explaining the reasons why. That is not happening," he told BBC Radio 4's Today programme.

"My concern is that, apart from the prime minister, who often has to do this with America, or [Foreign Secretary] Jack Straw, no other member of the Cabinet is actually now stepping up to the mark and doing what I think they have to do."

He said ministers should "go and talk to the public via the various broadcast mediums and persuade them there is a case".

Passionately

Mr Duncan Smith said he would prefer to see a further UN resolution on Iraq but argued that ultimately the UK must act in its own interests.

"I want passionately for the United Nations to take this opportunity to see off what I think is the biggest threat to world peace at the moment which is rogue nations developing these weapons [of mass destruction] with a mind to use them as terrorist weapons....

"I think this is a critical moment for the UN.

"If it fumbles this one we could see in the next five to 10 years some of the worst atrocities around the world because ... world leaders failed to stand up to their basic reason for being in government which is to protect their own citizens."