The Cabinet has lined up to support the prime minister's tough stance on Iraq.

Deputy prime minister John Prescott told Labour's spring conference in Glasgow that the British public should trust Blair over the issue of Iraq.

The show of support was the first stage of the response to the massive anti-war protests on Saturday.

Prescott claimed the prime minister had a moral case to back military action against Saddam Hussein.

"In situations like this, the job of a leadership is to take action because it is right and just. Such actions are rarely popular," he said.

"Tony Blair is such a leader and I trust him to make the right judgements in the interests of the British people and those of the wider world community."The deputy prime minister told delegates that the dispute over Iraq's weapons of mass destruction could be compared with each of the military conflicts Tony Blair had dealt with since coming to power.

"I trusted him when he said that we had to act in Sierra Leone when our TV screens were filled with horrific pictures of small children with arms and legs hacked off in a vicious civil war. The people of Sierra Leone were grateful when British military action averted a bloodbath in their country," he said."I trusted him when he said that the people of Kosovo needed our help because the UN was unable to stop the massacre of Kosovan Muslims because of a veto in the Security Council. Many said that military action could not stop genocide and ethnic cleansing in Kosovo. And yet it did."

Party chairman Dr John Reid said the prime minister would take on board the message from the anti-war marchers.

But he warned that taking the option of no action against Saddam would fail.

"It is between doing something to protect the world and people in Iraq, or doing nothing, " he said.

Health secretary Alan Milburn said showing solidarity was vital to the Labour Party.

Conservative leader Iain Duncan Smith, in his first response to the protest, broadly supported the prime minister's position and demanded that the UN takes action against Saddam.

"If the UN will stand up to this man, there is a chance that, once and for all, we may rid ourselves of terrorism and those who support it. If it does not, we could face very serious consequences," he said.

"If Tony Blair as prime minister does what is right, as I believe it is, for the British people to protect them from what could turn out to be catastrophic consequences if Saddam Hussein is left with his weapons of mass destruction, we will continue to take the same view."