By Daniel Béland

November 15, 2026

As a result of a confluence of factors, Canadians have been treated to a rolling seminar in by-elections since the three that secured a majority government for Prime Minister Mark Carney in April of this year.

In the 45^th Parliament that opened May 27^th 2025 with the throne speech from King Charles, there have been seven federal by-elections, all held this year. All but one — the one Conservative Leader Pierre Poilievre required to return to the House of Commons after losing Carleton in 2025 — have been won by Carney’s Liberals.

The six new by-elections scheduled for December 7th will make 13 in a year — a clip not seen since 1950, per The Writ’s Éric Grenier…back when MP mortality was a bigger cause of vacancies.

And these by-elections present different tests for two different leaders for whom the gap between expectations and results will be a disproportionate takeaways element.

As Lori Turnbull suggested in her recent Policy Magazine column, the Conservatives, “in order to give caucus, the movement at large, and the Canadian public assurance that the party is able to offer a clear and competitive alternative to Mark Carney’s Liberals,” must keep the Ontario riding of Brantford-Brant South, and win decisively in their Saskatchewan stronghold of Yorkton-Melville.

Although Turnbull is right to suggest that Pierre Poilievre is likely to stick around as Conservative leader even if the party fails to win both seats (none of his potential replacements wants to run against Carney, at least not yet) this scenario will reinforce the narrative that Conservatives are not competitive electorally under his leadership against Carney’s Liberals, who remain well ahead in national polls.

For his part, Carney isn’t going anywhere, whether December 7^th registers another clean sweep or not. So, the stakes of these by-elections have less to do with the survival of leaders than with the momentum of trends, and the three votes taking place in Quebec that day are especially interesting to watch.

Each of the Quebec by-elections will be a significant test for the Liberals, especially after the precedent of the party’s stunning win in Chicoutimi-le Fjord in the Ontario, B.C. and Quebec by-elections of August 31^st.

First, there is Laurier-Sainte-Marie, a majority francophone Montreal riding known for its left-leaning politics. Incorporating parts of several Montreal boroughs (i.e., Centre Sud, Plateau Mont-Royal and Ville Marie), this riding was held by former Bloc leader Gilles Duceppe from 1990 to 2011, when NDP candidate Hélène Laverdière defeated him in Jack Layton’s Orange Wave.

Re-elected in 2015, Laverdière lost in 2019 to environmentalist and star Liberal candidate Steven Guilbault, who soon joined cabinet and was re-elected in 2021 and 2025. Unhappy with the energy-development memorandum of understanding (MOU) between Alberta and the federal government, Guilbault resigned from cabinet in late November 2025. In late May, further dissatisfied with the Carney government’s energy and environmental policies, he announced he would leave the House of Commons, something he officially did in late August.

At the 2025 general election, Guilbault received 52 percent of the votes and, even if a growing number of progressive voters well represented in Laurier-Sainte-Marie are increasingly upset about the Carney government’s right-leaning economic and environmental policies, the Liberals are widely expected to win in that riding come December 7.

To increase their odds of keeping the riding, the Liberals have recruited a star candidate: former Desjardins CEO Guy Cormier, who is well respected in Quebec and has much in common with our former-central-banker Prime Minister.

The stakes of these by-elections have less to do with the survival of leaders than with the momentum of trends, and the three votes taking place in Quebec that day are especially interesting to watch.

The good news for the Liberals is that Cormier will face lesser-known candidates: For the Bloc, Zumretay Arkin, former Vice President of the World Uyghur Congress; for the Conservatives, Mathieu Fournier, who received only about 9% of the votes last year; and for the NDP, Nimâ Machouf, an epidemiologist who ran and lost in Laurier-Sainte-Marie in 2019, 2021, and 2025.

Located right next to Laurier-Saint-Marie, Rosemont-La Petite-Patrie is another majority-francophone Montral riding associated with left-leaning politics. Held by the Bloc from 1990 to 2011, the riding saw Alexandre Boulerice, a former journalist active within the province’s labour movement, swept in with that NDP Orange Wave in 2011. Re-elected in 2015, 2019, 2021, and 2025, he announced in late April that he would vacate his federal seat to run for Québec Solidaire in the October 5th Quebec general election, and is now the MNA for Gouin. Boulerice’s departure from the House of Commons means that the NDP no longer has an MP in Quebec.

In April 2025, Boulerice was re-elected with 41 per cent of the votes, more than 9 points ahead of Liberal candidate Jean-Sébastien Vallée, a significantly less impressive victory than in 2021, when he had finished 25 points ahead of then Liberal candidate Nancy Drolet.

Because the Liberals gained much ground in the riding between 2021 and 2025 election and because of the departure of Boulerice, who was re-elected several times based on his personal popularity, the Liberals have a real shot at winning Rosemont-La Petite-Patrie, a seat they have not held since 1984.

Vallée, a community leader well known in the riding, is running again for the Liberals and he is facing NDP candidate Pierre Céré, the former spokesperson for the National Council of Unemployed Workers, Bloc candidate Alexandre Curzi, the former general director of l’Union des artistes (UDA), and Conservative candidate Osmar Llanos Martinez, whose party received less than 7 per cent of the vote in the riding last year.

While on December 7^th, the results in Laurier-Saint-Marie and Rosemont-La Petite-Patrie should tell us a lot about the capacity of Prime Minister Carney’s Liberals to win in left-leaning Montreal ridings, the by-election in Saint-Hyacinthe-Bagot-Acton is clearly a test for the Bloc, which held the seat between 1993 and 2011 and, after NDP victories in 2011 and 2015, from 2020 to 2025.

As in Rosemont-La Petite-Patrie, this by-election is taking place because the incumbent, in this case Bloc MP Simon-Pierre Savard-Tremblay, left his seat to run provincially on October 5^th. He is now the MNA for Saint-Hyacinthe and a junior minister in the new Parti Québecois’s cabinet. At this stage, in a context in which it is lagging well behind the Liberals in the polls across the province, the Bloc is trying hard to keep that riding and prevent the Liberals from winning, something they have not done there since 1980.

It is possible for them to do so, as they finished about 10 points behind the Bloc last April, at a time when the Liberals were less popular than they are now in the province. If the Liberals can find a way to win, however, this would be a major show of force for the party outside of Montreal.

While there is a by-election in Saint-Hyacinthe-Bagot-Acton because the incumbent left to run provincially, the Liberal candidate this time around is former Coalition Avenir Québec (CAQ) MNA Chantal Soucy, who held the Saint-Hyacinthe provincial seat from 2014 to August, when she did not stand for re-election.

She is facing a strong contender in Bloc candidate Caroline Émond, who has national and international experience within the dairy industry, which is a key asset in a riding where the agrifood sector looms large. As for Luc Brodeur-Jourdain, the Conservative candidate, he has virtually no chance to win, as this is clearly a race between the Bloc and the Liberals, as it was in April 2025.

On December 7th, the Liberals would love to triumph in the three Quebec by-elections and Saint-Hyacinthe-Bagot-Acton is where they face the strongest competition.

While Carney only needs to win one of the three Quebec ridings to avoid losing ground in the House of Commons, there is a serious shot in at least two of them, and perhaps even three.

So far, Carney’s strategy of securing and maintaining a governing majority through by-elections has worked. Many Canadians seem to have processed it as both further evidence of his political acumen and a welcome alternative to a federal campaign so soon after the last one.

What December 7^th will be testing above all is whether, especially in Quebec — where political acumen is always a ballot question — that tacit agreement with voters will hold as his policy choices give them more to judge when given the chance.

 A fellow of the Royal Society of Canada, Policy Columnist Daniel Béland is professor of political science and director of the McGill Institute for the Study of Canada at McGill University.