Stephen Harper is refusing to say whether he would accept a decision by the Governor-General to hand power to the opposition parties in wake of the May 2 election.
Conservative supporters booed a CBC journalist at a Greater Toronto Area campaign stop Saturday morning after he challenged the Tory Leader on the matter.
Mr. Harper is warning voters the next government will either be a Tory majority or a coalition government led by the New Democrats. He warns a Conservative minority would be short lived, defeated by a coalition.
But he declines to say whether he'd accept a decision by the Queen's representative in Canada to give an opposition party the chance to govern - rather than, say, demanding the Governor-General call another election instead.
With just days before a ballot, he says it's a hypothetical question.
Mr. Harper however has spent the entire race since March 26 campaigning on a hypothesis: that his rivals would oust him from power should he fail to win a majority and instead form a coalition to take office.
"I am not going to get into those kinds of speculation," he said at a campaign stop north of Toronto. "We are running to win. " CBC reporter Terry Milewksi tried several times to get Mr. Harper to respond, accusing him of refusing to answer the question. He was asking on behalf of journalists covering the Harper campaign.
Tory supporters jeered and booed the reporter and a member of the audience shouted "shut down the CBC!" - a suggestion that drew loud applause from partisans.
Mr. Harper appeared at one point to be trying to quell the audience.
"I am not going to speculate on hypotheticals. We're in this to win," he said.
The Conservative Leader came close to losing the Prime Minister's Office in late 2008 when the Liberals and NDP united to form a coalition backed by the Bloc Québécois that was poised to defeat him.
He asked the Governor-General to prorogue Parliament, temporarily shuttering the Commons until he could return with a big-spending stimulus budget that dampened the Liberal Party's enthusiasm for the coalition.
According to a best-selling book published in 2010, Mr. Harper contemplated appealing to the Queen in the event Governor-General Michaëlle Jean refused to prorogue Parliament during the 2008 constitutional crisis.
Kory Teneycke, who was then Mr. Harper's director of communications, is quoted in Lawrence Martin's Harperland as saying an appeal to Westminster was one option under consideration.
According to Harperland, Mr. Teneycke maintained, in an interview well after the event, that it would have been "just unheard of" for the Governor-General to refuse a request for prorogation by a Prime Minister who had already survived a vote of confidence in the Commons.
When Mr. Teneycke was asked what other avenues the Prime Minister was exploring in case the decision had gone against them, he responded:
"Well, among them, the Queen."
The question became moot when Ms. Jean acceded to Mr. Harper's request for prorogation, but not before making him and the nation wait two hours.
Never since Confederation has a prime minister appealed directly to the Queen when frustrated by the decision of a governor-general. The political consequences had Mr. Harper done so, in those fevered weeks when the opposition parties tried to force the Conservatives from power - and the PM responded by having Parliament shut down - are difficult to contemplate.
Constitutional scholars have said it's unlikely the Queen would have agreed.