As voters head to advance polls this week, some will cast ballots in ridings that have been identified by pundits and projections as battlegrounds — ridings that should be close and could elect a new party.

Here are four Ottawa-area ridings, in alphabetical order, that will be worth watching closely as results come in June 12.

Glengarry-Prescott-Russell

This mainly rural riding has a large francophone population, one of the highest in Ontario.

Liberal Grant Crack won the election in his first attempt in 2011, beating Progressive Conservative candidate Maralissa Gosselin by 1,372 votes.

This time, he's facing the NDP's Isabelle Sabourin and PC Roxanne Villeneuve, the daughter of former provincial cabinet minister Noble Villeneuve.

University of Ottawa professor Gilles Levasseur said agricultural issues, including questions around the long-term viability of the Alfred college, loom large.

"For the average population, they know there's a solution but they know it's temporary… there's still the question of what's next," he said.

University of Ottawa professor Luc Turgeon said the riding demographics mean a non-Liberal MPP would be viewed as a surprise.

"It's a riding that for a long time had a Liberal (MPP Jean-Marc Lalonde) that was fairly popular and there for a fairly long time," he said.

"Glengarry-Prescott-Russell was just created in the 1990s, it has always been represented by a Liberal, it has a fairly large francophone population and in general, francophones tend to vote Liberal," said Turgeon.

Lalonde won his last race in 2007 by 13,418 votes.

​Ottawa-Orléans

Liberal Phil McNeely won three elections in this east-end riding, but he's given way to Marie-France Lalonde in this campaign.

Marie-France Lalonde

Marie France Lalonde is trying to keep Ottawa-Orléans in Liberal hands after Phil McNeely decided not to run again. (Andrew Foote/CBC)

She'll be trying to keep the seat in her first try, going up against returnee Andrew Lister of the PCs and Prosper M'Bemba Meka of the NDP.

"Phil (McNeely) has tackled several big issues, I'm willing to and I'm ready to tackle the next step," Lalonde said, adding that he's helped her out when she's canvassing.

"I didn't get into politics thinking it would be easy but I'm here to represent the people of my community. I've done this for 15 years at various levels."

Turgeon said the riding is interesting not only for the lack of an incumbent, but the fact McNeely won by 2,854 votes in 2011 — a margin over 7,000 less than in 2007.

"The dynamic is difficult for the Liberal candidate, she has to run at a time when her party is not especially popular," he said.

"I think her best hope at the end of the day is the lack of popularity of some elements of (Tim Hudak's) platform, especially in a city like Ottawa with a lot of public servants."

"The PC candidate, (Andrew) Lister, is able to speak French and he tries to make sure he showcases himself as a bilingual candidate," Levasseur said.

"The other Liberal candidate is… francophone so right there, she's able to capture (part of the) population."

Ottawa South

John Fraser kept the seat Dalton McGuinty retired from in a summer 2013 byelection, beating Matt Young of the PCs by 1,278 votes.

Fraser, Young and NDP candidate Bronwyn Funiciello are back, 279 days after the byelection.

"It wasn't as tight as some people had expected," Turgeon said, noting the riding had gone Progressive Conservative for 50 years until Dalton McGuinty Sr. was elected in the 1987 election.

Levasseur said the on-the-ground game is interesting and important here.

"If you look at the geography of Ottawa South it's a very big physical riding; if you take Ottawa-Vanier it's concentrated, if you look at Ottawa West-Nepean, it's concentrated," he said.

"It takes a lot of energy, a lot of drives."

The riding has the largest percentage of Arabic-speaking residents in the province and 23 per cent of residents are immigrants.

Ottawa West-Nepean

Randall Denley is trying to do provincially what John Baird has done federally — take Ottawa West-Nepean and turn it blue.

The PC candidate and former newspaper columnist lost to ex-Ottawa mayor and current Liberal Bob Chiarelli by 1,009 votes in the last campaign.

If that's not enough name recognition, former MPP and Ottawa city councillor Alex Cullen is running for the NDP.

"People like Alex Cullen for what he's done in the past… he did do some good as a city councillor," Levasseur said.

"It will have some impact on the Liberals, you're dividing the vote… people have to choose and it will be a strategic move versus an emotional move."

While these three candidates are well-known in Ottawa, Turgeon said it's important to remember that most voters will think first about party leaders.

"I'm not saying local candidates don't matter, but they're not the primary determinant of vote," he said.

"People will vote Liberal because they're either a long-time partisan of the party and will vote Liberal whoever is the candidate, or they'll vote for the party because they like Kathleen Wynne, for example," he said.

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