Eastern Ontario isn't usually an electoral battleground. Only a single seat changed hands in the 2014 provincial election. In previous elections, only one or two seats flipped from one party to another.

That pattern is likely set to change when Ontario goes to the polls next week, as the Liberals struggle to hold off the PCs and New Democrats in what has been traditionally one of their most reliable bastions of support.

The Progressive Conservatives and Liberals split eastern Ontario evenly between them in 2014. The PCs took most of the rural ridings in the region, while the Liberals mainly took the urban seats in Ottawa, Peterborough and Kingston.

The vote in the region was also close, with the Liberals taking 39 per cent and the PCs 38 per cent. The New Democrats trailed at a distance with 17 per cent, while the Greens took five per cent of ballots cast in eastern Ontario four years ago.

But now, the region appears to be headed for a significant swing.

The latest numbers from the CBC Poll Tracker, an aggregation of all publicly available polling data, put the PCs in first place in eastern Ontario with 41 per cent support. That's well within the PCs' normal range of support in the region; the party captured 36 per cent in 2007 and 42 per cent in 2011. So the PCs appear to be holding their core vote in eastern Ontario.

The Liberals have lost theirs. Polls put the party at just 22 per cent in the region, down 17 points from the Liberals' performance in 2014. The New Democrats have benefited most from this fall and have moved into second place in eastern Ontario, with 30 per cent support.

The Greens follow at five per cent, unchanged from 2014, while two per cent of eastern Ontarians say they will vote for another party.

(The Poll Tracker is updated daily and the numbers can change quickly. Check out the latest projections here.)

The Libertarians are running candidates in every riding in eastern Ontario. While no other smaller party is running even a half-slate in the region, one boasts an incumbent MPP. Jack MacLaren is running for re-election under the Trillium Party banner in Kanata–Carleton after he was expelled from the PC caucus in 2017.

Saving the Liberal furniture

Now that the Liberals have dropped so significantly in the polls, their seats in the region are vulnerable — every one of them. Nevertheless, eastern Ontario is the party's best region in the province after Toronto and is key to their hopes of retaining official party status in the Ontario legislature.

That means winning eight seats — and the Liberals have no assurances of doing even that well.

But unlike the situation facing them in some other regions of the province, in eastern Ontario the Liberals are still in the running in a number of ridings. The party can't be written off in Glengarry–Prescott–Russell, Orléans, Ottawa South and Ottawa–Vanier. They have an outside chance of retaining Peterborough–Kawartha and Ottawa West–Nepean as well.

They also could find themselves shut out entirely.

The Liberals have a few advantages that might help them save some of the furniture in eastern Ontario. The party has deep historical roots in the region. Glengarry–Prescott–Russell has voted Liberal in every election since 1981. Ottawa–Vanier has been painted Liberal red for nearly half a century.

They also have a few cabinet ministers running for re-election: Marie-France Lalonde (Orléans), Yasir Naqvi (Ottawa Centre), Bob Chiarelli (Ottawa West–Nepean), Nathalie Des Rosiers (Ottawa–Vanier) and Jeff Leal (Peterborough–Kawartha).

And the last ace up the Liberal sleeve might be the francophone vote. Traditionally, it tilts strongly in favour of the Liberal party. Glengarry–Prescott–Russell is 59 per cent francophone, while over a quarter of voters in Orléans and Ottawa–Vanier list French as their mother tongue.

So it was no surprise to see Kathleen Wynne in eastern Ontario speaking French to locals on Thursday — something neither Andrea Horwath nor Doug Ford is able to do.

NDP in uncharted territory

Ever since the NDP was defeated in the 1995 provincial election, the party has never held a seat in eastern Ontario. Even in the 1990 vote that propelled them to their only win in the province's history, the NDP took just a single seat east of Kingston.

But with the NDP now in second place in polls in the region, the party could score some wins that would have been almost inconceivable only weeks ago.

Ontario NDP Leader Andrea Horwath campaigning in Ottawa, where the party has a chance for a breakthrough. (Patrick Doyle/Canadian Press)

In addition to Ottawa Centre — the one seat east of Kingston the party captured in 1990, and a riding that was won by the federal NDP as recently as 2011 — the New Democrats could pick up Kingston and the Islands and Peterborough–Kawartha, areas of the province where the NDP won seats under Bob Rae.

With a little luck, the party could emerge victorious in three-way races in Ottawa South, Ottawa–Vanier and Ottawa West–Nepean as well. These are parts of the province that have never voted for the NDP.

No more easy pickings for the PCs

At the outset of the campaign, eastern Ontario looked ripe for PC gains. The Liberals were down in the polls and the PCs were up, and the NDP wasn't even a factor in the region.

But the PCs have slipped a little in eastern Ontario, putting some of their potential gains in doubt — seats like Glengarry–Prescott–Russell and Orléans. And the NDP surge could put some seats at risk that should have been easy wins for Ford.

Ontario Progressive Conservative Leader Doug Ford spent his first day of the campaign in eastern Ontario. (Patrick Doyle/Canadian Press)

Unexpectedly, the PCs could be forced to fight off the NDP in a number of ridings: Hastings–Lennox and Addington, Northumberland–Peterborough South, Bay of Quinte and Stormont–Dundas–South Glengarry, in addition to the Ottawa-area seats that any of the three parties could win.

It could make for an election night far more interesting than anything eastern Ontario has seen for a long time.