As Andrew Coyne notes, it's still an open question how far Harper would go in trying to cling to power under all kinds of circumstances:
As prime minister, Mr. Harper would retain a number of prerogatives as he looked for ways to hang on to power, one of which would be to avoid recalling Parliament for as long as he could. After the 1979 election that returned a Conservative minority, Joe Clark did not recall the House for five months.But even worse, it's far from clear that Harper would be prepared to accept the judgment of the Governor-General even for the moment in allowing some combination of other parties to form a government.
Mr. Harper might use the interval to curry favour with voters, or to sow divisions in the opposition, the better to deter them from defeating him. (I do not hold with those who think that, merely for having been reduced from a majority to a minority, Mr. Harper would resign as leader or be pushed out. “The longer I’m prime minister” and all that.) But eventually Parliament would have to sit, which is where the governor general comes in.
If the opposition did wish to replace the government, they would have to move fast. The longer they waited, the more that Mr. Harper might make the argument to the governor general that his defeat required the dissolution of the House and the calling of a new election. Whereas an immediate defeat in the House would seem to make another election, so soon after the last, dilatory. The way would be open for the opposition to propose instead that power be transferred to them.
I say “would seem to,” because it’s not a given Mr. Harper would concede the point. Power, once possessed, is not easily given up. Indeed, everything he has said publicly has been to pour scorn on the idea as fundamentally undemocratic, a kind of coup, launched by a “coalition of the losers.” The “highest principle of Canadian democracy,” he said at the height of the 2008 crisis, “is that if one wants to be prime minister one gets one’s mandate from the Canadian people.”
In other words, the prime minister would be tempted to “do a King-Byng” — to re-enact the crisis of 1926, when Mackenzie King, rather than accept defeat in the House as the cue to yield power to Arthur Meighen’s Conservatives (who, after all, had 15 more seats than King’s Liberals), insisted the governor general, Byng, call new elections. Byng refused, Meighen took over (briefly) as prime minister, and King used the issue to win the next election. The precedent can’t be far from the current prime minister’s mind.
Remember that in 2008, Harper was prepared to demand that the Queen override any decision of the Governor-General to the effect that his government was accountable to Parliament - and planned to accompany that course of action with an attempt to shut down the country, holding the Canadian public for ransom. And in 2011, Harper refused to offer any answers whatsoever as to whether he'd accept a constitutional transfer of power.
Of course, the 2011 example makes it clear that we may not be able to get answers in the midst of an election campaign, particularly from Harper himself. But there's plenty of time now to push Harper and his slate of candidates to tell us exactly how much damage they're willing to do to stay in power. And the fact the answer looks to be "as much as it takes" itself offers a compelling reason not to leave anything to chance.