Prime Minister Jean Chretien said Monday Canada will not join a military campaign against Iraq without the support of the United Nations Security Council.

"If military action proceeds without a new resolution of the Security Council, Canada will not participate," Chretien said to cheers of Liberal and NDP MPs in Parliament.

"We believe that Iraq must fully abide by the resolution of the United Nations Security Council. We have always made clear that Canada will require the approval of the Security Council if we were to participate in a military campaign."

"Over the last few weeks, the Security Council has been unable to agree on a new resolution authorizing military action. Canada worked very hard to find a compromise to bridge the gap in the Security Council. Unfortunately we were not successful," Chretien said.

Chretien said he still hoped that war could be avoided but admitted he was "not very optimistic."

"If there is a war, of course Canada will be there to help the victims of a war," Chretien said.

Chretien added that Canadian forces currently participating in the war against terrorism will continue to be deployed in the Arabian Sea and Afghanistan. And he said Canadian forces would likely be involved in a peacekeeping or reconstruction role after any possible U.S.-led military action against Iraq.

Opposition Leader Stephen Harper said the government's decision to send troops to Afghanistan while failing to support the U.S. position on Iraq is sending mixed signals to Canada's allies.

"I think what we're going to see is a very different world in terms of security," Harper told reporters. "Canada has distanced itself from our historical allies and is really nowhere on the map.

"It is very likely that the U.S., Great Britain and their allies will be at war with Iraq. We'll (Alliance Party) be cheering for our allies and if the Liberals are going to be cheering for Saddam Hussein then they should have the guts to say so."

Defence Minister John McCallum denied that Ottawa is sending a contradictory message.

"We support the UN and our multilateral decisions...and secondly we support our allies in the fight against terrorism."

On Monday evening, U.S. President George Bush said Iraqi President Saddam Hussein and his family have 48 hours to leave Iraq or face military action.

In a televised speech, Bush said efforts to disarm Iraq have failed and that the time for military action has arrived.

After Bush's ultimatum, Foreign Affairs Minister Bill Graham told reporters he reaffirmed Canada's position with U.S. Secretary of State Colin Powell about two hours before Bush's speech.

"We had a frank and open discussion," Graham said. "I told him we require a clear UN mandate.

"He told me that Canada and the United States had always worked closely together. I told him we would continue to work with them in the war against terrorism."

Graham downplayed earlier remarks by the opposition claiming Canada's stance on Iraq will harm relations with the U.S.

"Colin Powell is always very respectful. He said that we have a difference of opinion with respect to the analysis of the current situation but that does not prevent us from being allies and friends and having very close links that go beyond a specific situation."

Graham said Canada doesn't agree with Bush's view that Saddam ouster and a regime change is essential to disarm Iraq. However, Graham says Canada won't stand in the way of a U.S.-led war on Iraq.

"We do not criticize the actions of others, but we clearly make a decision principled on our own basis of what we should do. And we do not believe we should be acting at this time.''

NDP House Leader Bill Blaikie said the government should go one step further and hold a vote in Parliament over the legitimacy of an attack on Iraq without a second resolution.

But Chretien rejected the idea, saying "the government has taken a very clear position."