Canada fills six empty seats on 7 December. Will Mark Carney's party gain any?
Canada votes on 7 December to fill six empty seats in parliament. Prime Minister Mark Carney's Liberals had two of them and are running in all six.
What happened
Prime Minister Mark Carney has set by-elections in six seats in Ontario, Quebec and Saskatchewan for , a chance for the Liberals to strengthen their thin majority.
Canada holds six by-elections on Monday . A by-election fills a seat in parliament that is left empty between general elections. Prime Minister Mark Carney announced the six on : three seats in Quebec, two in Ontario and one in Saskatchewan.
Federal by-elections will be held on Monday, December 7, 2026, in the ridings (electoral districts) of Brantford–Brant South (Ontario), Laurier–Sainte-Marie (Quebec), Rosemont–La Petite-Patrie (Quebec), Saint-Hyacinthe–Bagot–Acton (Quebec), Scarborough North (Ontario) and Yorkton–Melville (Saskatchewan).
Elections Canada, news release,
Carney’s Liberals have 173 seats in the Commons, the elected chamber of Canada’s parliament. That is a thin majority, so losing all six would not stop them governing. Two of the six seats were Liberal. The other four were won by the Conservatives (two), the Bloc Québécois and the New Democratic Party (NDP), and the Liberals have candidates in all of them.
The Conservatives face a split in Brantford-Brant South. Their leader, Pierre Poilievre, chose the city’s mayor, Kevin Davis, as candidate instead of letting local members pick one. A long-time local Conservative now runs on his own, without a party, backed by Phil McColeman, who held the seat for the Conservatives before Larry Brock. In the Conservatives won the seat with 52.4% of the vote, against 41.1% for the Liberal Joy O’Donnell, who is standing again.
The NDP is defending its only seat in Quebec, Rosemont-La Petite-Patrie. Alexandre Boulerice, its MP there since 2011, sat as an independent before he left for Quebec’s own parliament. He won 41.0% there in 2025, while on the same day the NDP got 18.8% next door in Laurier-Sainte-Marie.
On the Liberals won all three by-elections held that day, and took Chicoutimi-Le Fjord in Quebec from the Conservatives with 51.6% of the vote. From July to September they also raised more in donations than the Conservatives. In Ontario polls close at 9:30 p.m. local time, and Elections Canada publishes results through the night, early on in Britain.
Sources: CBC News (2, 3), Elections Canada (2, 3, 4, 5, 6), The Globe and Mail (2)
The Pattern
We looked for cases where Canada filled an empty seat in parliament by a by-election while the government had a majority of ten seats or fewer, and had already taken a seat from the opposition at an earlier by-election in the same parliament. We found nine such by-elections, from 1998 to 2000, on five polling days under the same Liberal government.
Show the other 7 cases
The Read
Past by-elections like these point to little change. In all seven where the governing Liberals had a candidate, they ended the day with as many seats as before: they kept their own seats and took none from the opposition. Only one seat in nine changed party, Sherbrooke in 1998, where the Bloc Québécois beat the Liberals by 0.61 points.
There are reasons for doubt. All nine come from one parliament and one government, on five polling days, and the main opposition then was Reform and the Progressive Conservatives, while today it is the Conservatives. No polling day then had more than one opposition seat with a Liberal candidate, and this time there are four. None of the nine had a split like Brantford-Brant South, where CBC says the Conservative candidate is “already expected to face an uphill battle against the Liberals”.
Sources: Elections Canada (2, 3), CBC News
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