As election day approaches, the road to power goes through Ontario

It's been a complicated federal election campaign, but as we approach next Monday's vote, it boils down to simple math.

In this election, there are 338 ridings at stake,121 of them in Ontario. Of those, 52 are in the Greater Toronto Area, with 25 in the city of Toronto proper. And perhaps most significantly, there are 15 new ridings in the province because of redistribution.

Given the changes and the sheernumber of seats up for grabs, it follows that winning in this province could make or break the parties' fortunes on the night of Oct.19.

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The road to a fourth victory for Conservative Leader Stephen Harper, certainly, goes throughOntario. That isaknownfact to three main federal parties.

The Conservatives elected 69 MPs in the 2011 federal election. But holding those seats is now only half the battle. They must also make gains if they are to stopwhat polls suggest isLiberal momentum.

That's especially true in the Greater Toronto Areaand in southwestern Ontario. It's why Harper has spent so much of his time, energy and political rhetoric in the region.

And in the next few days leading up to election day, expect more of his hard-hitting attacks on the Trudeau Liberals, witha warning that they will do to the country what PremierKathleen Wynne is doing in Ontario sending "shockwaves throughout our economy." (That was a message test-driven over the weekend by Toronto Conservative candidate Joe Oliver.)

But Conservative concerns now go beyond Wynne and her government they also focus onan apparent federal Liberal encroachment into Tory-held ridings.

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The goal for the Tories in Ontario will be to reignite old messages about the Liberals and play on the theme that this election is not the time for change, especially if that change includes Liberal Leader Justin Trudeau.

Liberals after NDP's Toronto seats

For the federal Liberals, who sustained a political body blow in 2011 that left their Ontario fortressinshambles, this week will be a blitz of seven or eight provinces, including Ontario.

Trudeau will workto solidify support while trying to shakeloose some undecided progressives.

His message will be direct: a Liberal vote is a vote to stop Harper,and the third-place NDP can no longer claim to be able to do that.

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Watch for the Liberals to spenda chunk of the week in Toronto ridings currently held by the NDP.

Could Peggy Nash be vulnerable in Parkdale-High Park?

Could Andrew Cash be in the same boat in Davenport?

Both New Democrats had comfortable but not overwhelming pluralities in the last election, and the Liberals are looking to make gains in both ridings.

But they also have their eyes on southwestern and eastern Ontario and the Hamilton area.

NDP moveto the centre

For the NDP, there's a sense of dja vu in this final week of the federal campaign, one that hasits roots in how Ontario NDP Leader Andrea Horwath ran her campaign in the 2014 provincial election.

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Like Horwath, federal NDP Leader Tom Mulcair saw his political future in a move toward the centre of the political spectrum in an appeal to middle-class voters.

But the centrist move flopped for the Horwath New Democrats in the 2014 provincial election.

If the polls are any indication, it appears momentum is not on Mulcair's side, though there are other factors at play, both in and out of Ontario.

So he has to show he's still in touch with the NDP's leftist past and also convince voters he and his party can stop Harper.

The campaign rhetoric will be focused on the negative: the Harper record including "the dangers" of the Trans-Pacific Partnership trade dealand the planned Trudeau deficits.

But he willalso stresswhat the NDP sees as "the real positives," in particularits$15-a-day child-care plan.

The road back for Mulcair and Harper will be difficult but not impossible. For Trudeau it's all about maintainingmomentum, especially in vote-rich Ontario.

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It is often said, aweek in politicscan be a lifetime.But for Mulcair, Trudeau and Harper there are also, in this baseball post-season, the words of the late, great Yogi Berra: "It ain't overtill it's over."

And next Monday may ultimately settle very little. A minority government, which polls suggest would be a likely outcome,may only give voters enough time to take down their lawn signsandthen put them back up.