Prime Minister Stephen Harper officially announced this morning four by-elections will be held Nov. 9.
The four ridings are in British Columbia, Nova Scotia and Quebec.
The Conservatives are downplaying expectations on the outcomes, with one party source saying they don't expect to win any of the races.
The two ridings up for grabs in Quebec - one in Montreal and the other an eastern riding that includes Riviere-du-Loup - are Bloc Quebecois strongholds.
A third riding in the Vancouver-area was held by the NDP. The fourth in Nova Scotia, was held by former Conservative-turned Independent Bill Casey, who split with the party.
The byelection announcement has been seen as a signal the Tories expect to survive Liberal attempts to topple them this fall and hold out hope for adding to their total.
Pollster Nik Nanos agrees that the Bloc Quebecois have a lock on the two Quebec ridings up for grab - in Montreal and in the eastern Quebec region of Riviere-du-Loup - where the nationalist party candidates won well over half the votes in 2008.
But the Nova Scotia riding held by independent Bill Casey, a former Conservative MP who had a falling out with Harper, could be in play, he said, now that the popular Casey has vacated the scene.
"You take (Casey) out of the equation, ridings usually revert to their normal pattern, so if they can field a strong candidate, they have a shot," he said.
The New Westminster, B.C. seat held by Dawn Black, who left for provincial politics, is also winnable for the Tories, he said. The well-liked Black won the riding by just over 1,000 votes last October and the Tories held the riding as recently as 2004.
Mr. Nanos said the Harper Conservatives are riding an upward momentum at the moment, with several polls showing them about six points ahead of the Liberals and starting to approach the 40-per-cent level believed needed for a majority.
"I don't see a downside for them calling the byelections now. Every seat they win gets them one step closer to majority territory," he said.
The Nov. 9 date is the earliest the byelections could be held, given the minimum 36-day campaigning period.