Whitby-Oshawa, Yellowhead byelections: What to watch

As voters in two federal ridings head to the ballot box today to fill the seats left vacant by the death of former finance minister Jim Flaherty and theretirement oflong-time ConservativeMP Rob Merrifield, it is the battle for second place thatcould turn out tobe the biggest story of the night.

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• Updated results of Whitby-Oshawa (Ontario) byelection
• Updated results of Yellowhead (Alberta) byelection

CBCNews.ca will be updating results in the two byelections after polls close tonight at 9:30 p.m. ET.

The tightening race in Flaherty's former Toronto-area riding may explain why Liberal Leader Justin Trudeau will make an appearance at the election night rally for Liberalcandidate Celina Caesar-Chavannes.

According to his office, Trudeau will address the crowd an hour after the polls close,by which pointenough numbers shouldhave rolledin to establish atrend, if notnecessarilythe winner.

Liberals a distant 3rd in 2011 election

Even the most optimistic Liberal strategists aren't predicting an upset win overthe Conservatives' candidate,former Whitby mayor Pat Perkins.

But there's a good chance theLiberal Party will at least muster amore impressiveshowing than it didduring the electoral darkdays of2011, whenTrevor Bardenscame ina distant third to Flaherty, with just14 per cent of the vote.

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That put him well behind New Democrat candidate Trish McAuliffe, who pulled in a more respectable 22 per cent,albeit one still dwarfed by the 58 per centsupport garnered byFlaherty during what would turn out to be his swan song on the hustings.

The New Democrats don't appear to be quite so confident in McAuliffe's vote-getting ability this time around at least, not enough to make sure their leader is within microphone range when the results come in.

Tom Mulcairhas instead been dispatched to St. John's, N.L. where he willbe at a nomination meeting to confirm the candidacy of incumbent NDP MP Ryan Cleary in Mount Pearl. Cleary will face off against former CTV host turned Liberal star candidate Seamus O'Regan in 2015.

The governing Conservatives can take comfort in the fact that, unlike recent western byelections in Fort McMurray-Athabascaand Brandon-Souris, Jim Eglinski isexpected to cruise tovictory in Yellowhead, which elected Merrifield with a whopping 77 per centshare ofthe vote in 2011.