Canada has said it plans to keep its 2,500-strong military mission in Afghanistan until the end of 2011, almost three years longer than initially scheduled, and wants to shift the focus to training Afghan forces.
The plan is dependent on NATO sending more troops to southern Afghanistan, where the mission is based.
A motion to get approval for the plan will be put to the House of Commons for a vote in March and its defeat would bring down the minority Conservative government, forcing a general election.
The combat mission in Kandahar - which is now due to end in February 2009 - has become one of the most controversial topics in domestic politics. Polls regularly show that around half of Canadians want the soldiers back on schedule.
The main Liberal opposition party backs the idea of keeping the troops in Afghanistan longer, but only if their combat role is ended. So far, 78 Canadian soldiers have died in Afghanistan, the majority killed by roadside bombs.
"The objective is to shift more and more responsibility to the Afghan army," said government minister Peter Van Loan, making clear that the troops would continue to carry out combat missions for the time being. "We aren't looking here for permanent bases and permanent stations in Afghanistan. We want the Afghan people to be able to run their own country," he told reporters.
The motion says Parliament "does not believe that Canada should simply abandon the people of Afghanistan after February 2009."
The government is committed to extending the mission as long as NATO commits an extra 1,000 troops to southern Afghanistan, and Ottawa procures helicopters and unmanned aerial reconnaissance vehicles.
Canadian officials are currently in Paris discussing whether France can send troops. Media reports say France is mulling the transfer of a 700-strong battle group.
The parliamentary vote on the mission will be held before a scheduled NATO leaders' summit in Bucharest in April that is likely to be dominated by troop numbers in Afghanistan. Liberal leader Stephane Dion said his party would propose amendments to the plan but stressed the combat part of the mission had to end next year. "If we are ambiguous ... it will be a never-ending mission," he told CKNW radio in Vancouver.
Deputy Liberal leader Michael Ignatieff noted that the government motion talked about a reduction in Canada's combat role and said this could form the basis of a compromise. Liberal legislators will discuss the matter early next week.
Mr Van Loan said the government was open to amendments but he also attacked Mr Dion, who the Conservatives portray as weak. "I, quite frankly, have difficulty knowing where the Liberals stand on this issue.... Mr Dion's position, so far as I can assess it, is one of 'I can't make up my mind'," Mr Van Loan said.
"I don't understand how you can say you keep the army there but they can't do anything.... You cannot leave our troops as sitting ducks in the field to be killed by the enemy."
Mr Van Loan played down speculation that the Conservatives would want to fight a quick election on the Afghan issue. "I don't think any political strategist .. would be going there and telling you, 'Hey, have an election on Afghanistan, that's a real winner for you'."