MONTREAL — The Conservatives’ operatives who have been shooting footage of Prime Minister Stephen Harper on his annual jaunt to the North presumably plan to use it for a campaign ad and not for a farewell video.

But this fall Harper will still have two significant opportunities to assess the temperature of the political waters before he takes the plunge and asks Canadians for a fourth mandate.

One test will involve actual voters in Ontario, the province that stands to determine the final outcome of the 2 015 election.

The second will take place within the narrower confines of the Conservative caucus and the House of Commons.

Each could have short and long-term consequences for the men who lead Canada’s three main parties but in particular Harper, who already has four campaigns and almost a decade in power under his belt.

Harper has until Oct. 25 to set a byelection date to fill the GTA seat left vacant in the wake of Jim Flaherty’s passing.

For as long as the former finance minister was its MP, the riding of Whitby-Oshawa was not on anyone’s list of top seats at play and that likely would not have changed had the Conservatives succeeded in bringing Flaherty’s widow, Christine Elliott, over to the federal arena.

But Elliott, who was reelected to the Ontario legislature in the spring, has set her sights on the provincial Tory leadership and Tim Hudak’s succession.

Whitby-Oshawa landed in the Conservative column in 2006 and Flaherty increased his share of the vote to more than 50 per cent over the two subsequent elections. But it was previously in Liberal hands and the party has been on a bit of a byelection roll since Justin Trudeau became its leader.

Flaherty’s former seat is also a rare GTA riding that can boast some solid NDP history. Ed Broadbent held it for as long as he was party leader.

Whoever ends up running for Harper in this riding might want to avoid banking too much on Flaherty’s ghost to keep non-Conservative challengers at bay. Earlier this summer the byelection that took place to fill Olivia Chow’s Trinity-Spadina seat illustrated the limits of such calculations.

This could be the last federal byelection before next year’s general campaign. The Conservatives, who have been plagued with a long string of mediocre poll results, including some that show them a long way off from the leading Liberals in Ontario, could use a strong win, if only to bolster party morale.

Ditto for the New Democrats. At the very least, they need to hang on to the second place they secured in 2 011. The Liberals, of course, are looking to maintain their pre-election momentum.

The byelection will be a must-watch for strategists and observers alike.

Moving inside the parliamentary beltway for the second test, the fall session of the House of Commons is expected to feature a decisive vote on a private member’s bill that purports to reverse the erosion of MPs’ influence.

Its author, Conservative MP Michael Chong, has secured the support of some of the opinion leaders within the government caucus. In a free vote it would have a decent shot at becoming law, especially if two dozen or more Conservative MPs who are not running for re-election feel freer to support it.

But that does not mean the prime minister or, for that matter, the other party leaders have cause to like the bill.

One of its key provisions would see a leadership review triggered at the call of 20 per cent of a party caucus, and a leader could be ousted on the basis of a majority vote of his MPs.

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If such a law had been in place in Canada this summer, chances are the Bloc Québécois Leader Mario Beaulieu would already be out of a job. He lost one quarter of his tiny caucus since taking on the leadership last June with another defection potentially to come.

Harper draws more inspiration than he cares to admit from Jean Chrétien’s example. Under Chong’s regimen, it would not have taken long into Chrétien’s third majority mandate for the Liberal caucus to seek a review of the prime minister’s leadership.

Chantal Hébert is a national affairs writer. Her column appears Tuesday, Thursday and Saturday.

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