Voters in four ridings in Ontario, Saskatchewan and British Columbia are casting ballots in federal byelections Monday.

The Liberals, who won in all four ridings during the last general election, are trying to retain their seats and avoid a repeat in the last round of byelections in Quebec when they lost all three ridings, including their bastion of Outremont that went to the NDP.

The four ridings are Toronto Centre, Willowdale, Vancouver Quadra and Saskatchewan's Desnethé-Missinippi-Churchill River.

Federal byelection candidate Bob Rae, right, and Liberal Leader Stéphane Dion, rear, arrive for a campaign rally in Toronto on Friday.
(J.P. Moczulski/CP)

Former Ontario premier Bob Rae, the best-known candidate in all the races, hopes to replace former Liberal cabinet minister Bill Graham in Toronto Centre. Graham held the riding for 14 years before resigning in July.

Liberal candidate Martha Hall Findlay hopes to win in Willowdale, which was held by Liberal Jim Peterson since 1988.

Rae said the Liberals face good odds in both Toronto-area byelections because voters seem fed up with being ignored by the federal government.

"I think the key thing we're hearing about is a real concern that the Harperite government is just not there for [Toronto] — it just doesn't care about us," he said.

"You've got [Finance Minister Jim] Flaherty knocking Ontario, saying Ontario and Toronto are lousy places to do business, lousy places to invest, and I think there's a sense that's just so contrary to people's interests."

Rae said the federal byelections also will help the Liberal party gauge how it's doing.

"They are a bit of a barometer of opinion and how things are going and what people feel about Mr. Harper's government and the alternatives," he said. "So we'll see how it goes."

Vote vital to Dion

Observers said Liberal Leader Stéphane Dion, who has made stops in all four ridings, must have at least three Liberal candidates win in the byelections to ensure his leadership won't suffer another blow.

"For Stéphane Dion, it's really another step in rebuilding the party, rebuilding the caucus, in a sense shoring up the unity of that caucus," said Michael Behiels, a professor at the University of Ottawa.

The New Democrats and Conservatives downplayed the significance of the byelections, saying the ridings are essentially the Liberals' to lose.

In Vancouver, former B.C. cabinet minister Joyce Murray is running in Vancouver Quadra, which has had consistent Liberal support since 1984.

Perhaps the toughest assignment belongs to Joan Beatty, another former New Democrat-turned-Liberal, who is running in Saskatchewan.

The Liberals won the riding by only 67 votes in 2006, and party insiders have said they wouldn't call it a disaster if the seat went to the Conservatives.

With files from the Canadian Press