The populations in Canada's three northern ridings are tiny, but their political value in the current federal election campaign is huge.

There are only three ridings stretching across Canada's northern frontier -- Yukon riding, Western Arctic and Nunavut -- and their combined population is a little less than Thunder Bay, Ont.

But by the end of next week, Prime Minister Stephen Harper, Liberal Leader Michael Ignatieff and New Democrat Leader Jack Layton will have all hit the hustings in the North, trying to shore up support and lend momentum to their local candidates.

Each of the three main parties has a legitimate stake in the region. Yukon is held by the Liberals, Western Arctic is in NDP hands, and Nunavut is held by the Conservatives -- and all three want to see their holdings grow.

The Conservatives in particular, said pollster Nik Nanos, are desperate to hold on to their Nunavut riding and make new gains wherever they can.

"We know that the northern ridings matter for Stephen Harper because he's made the North a personal priority," Nanos told CTV.ca.

"He has gone to the North a number of times, he has talked about economic development in the North, he's talked about security in terms of Canada's borders in the North and I think it would be fair to say the Harper Conservatives see the North as a priority."

In more basic terms, Nanos said, the North matters because the Conservatives simply need to win each and every new seat they possibly can -- without losing any that they currently have -- in order to achieve the majority they seek.

Conversely, the Liberals need every seat they can get in order to stop them, and the NDP's power in Parliament could become significant, or negligible, depending on the difference of a few seats.

"Think of it as a recognition from all the federal parties that at this point in time this is unlikely going to be a breakthrough election for any of the parties, but that we're probably looking at incremental changes," Nanos said.

"And if that is the case, each of the parties has a stake in holding onto what they have in the North."

Following are some key details about Canada's three northern ridings:

Yukon

• Population: 31,227 (roughly half the population of Medicine Hat, Alta.)
• Size: 482,443 square kilometres
• Incumbent MP: Larry Bagnell (Liberal)

Western Arctic

• Population: 41,464 (roughly the size of Timmins, Ont.)
• Size: 1,346,106 square kilometres
• Incumbent MP: Dennis Bevington (NDP)

Nunavut

• Population: 29,474 (roughly the size of Cranbrook, B.C.)
• Size: 2,093,190 square kilometres
• Incumbent MP: Health Minister Leona Aglukkaq (Conservative)

Tough battles are shaping up in each of the ridings -- in areas where the difference between first and second place is often just a few hundred votes.

The Conservatives have an important cabinet minister in Nunavut, Health Minister Leona Aglukkaq, who is in a tough fight against former Nunavut premier, Liberal candidate Paul Okalik.

In the Yukon, a riding with a population of just 30,372 and a land mass of half a million square kilometres, Liberal incumbent Larry Bagnell is fighting against Conservative challenger Ryan Leef.

Bagnell is in a tough spot -- after promising his largely gun-toting constituents he would vote in favour of abolishing the long-gun registry, he was forced last fall to vote on party lines to keep the registry alive.

Reef took aim at the discrepancy right from the outset of his campaign, arguing that Bagnell said one thing and did another, and has lost voters' trust.

In Western Arctic, NDP incumbent Dennis Bevington is facing challenges from the Liberals' Joe Handley, a former premier of the territory, and the Conservative candidate Sandy Lee, a former territorial cabinet minister.

And the leaders of both challenging parties were in Yellowknife last week to support their candidates' bids to unseat the incumbent.

But Nanos said races in Canada's north are a different beast than elsewhere in the country. Despite the sheer size of the ridings -- communities can be separated by hundreds, if not thousands, of kilometres -- personal relationships go much further than party policies.

Nanos said it's much more likely in northern ridings that voters will cast a ballot for the candidate they know, rather than the party that most closely matches their political stripe.

"It's very different from any kind of urban election campaign because it is one-on-one, pond-hopping to communities where candidates are doing a lot of door knocking and a lot of radio and interacting with small groups of voters, many of whom are familiar with the candidate," he said.

"Just because of the scale and the cultural environment those personal relationships are much more important in those ridings."