By Daniel Béland

August 12, 2025

On Monday evening, the governing Coalition Avenir Québec (CAQ) lost its third byelection in a row, this time with a catastrophic defeat in the provincial riding of Arthabaska. Receiving barely 7% of the votes in total, the CAQ finished in fourth place in a riding they had won by more than 50% of the vote less than three years ago.

Meanwhile, the Parti Québécois is celebrating yet another byelection victory, with former Radio-Canada radio personality Alex Boissoneault having won Monday. While it only won three seats in the 2022 general election, the PQ will now have six MNAs. With this victory, the indépendantiste party confirms its momentum as the main perceived alternative to the CAQ, which has long been struggling in opinion polls as people have grown disenchanted with Premier François Legault’s management style and policy performance.

Overall, barely 15 months ahead of the next Quebec general election, the main takeaway of this by-election is that the CAQ is in electoral disarray, and the PQ clearly has the wind in its sails. Because the PQ supports a third independence referendum by 2030, next year’s Quebec campaign could feature separation as a key electoral issue. Such a scenario would be disastrous for the CAQ, which advocates for a nationalist third way beyond federalism and separatism, as it is the Liberal Party of Quebec and the PQ that “own” the two sides of this debate. The CAQ remains in power but, electorally, it increasingly feels like a spent force.

Unfortunately for the CAQ, Arthabaska is considered a reliable bellwether for provincial parties among francophone voters. Located south of the Saint-Lawrence between Montreal and Quebec City, this heavily francophone riding has existed since 1890. Liberal-controlled for the first 45 years of its existence, Arthabaska alternated between Liberal and Union Nationale MNAs between 1936 and 1976, when Jacques Baril won the riding for the Parti Québécois (PQ). He served as its MNA until 2003, with the exception of period between 1985 and 1989, during which the Liberals held the riding. Turning red again in 2003, the riding shifted to Action démocratique du Québec (ADQ) control in 2007 for only one year, after which it became Liberal again.

Before the triggering of this by-election, the riding had been under CAQ control since 2012. This was the first general election in which the party, which was created the year before, presented candidates, winning only 7 seats out of 125. The fact that Arthabaska was one of these handful first CAQ seats makes Monday’s defeat of the party especially meaningful, because the party had won the riding again easily in 2014, 2018 (with more than 60% of the vote), and 2022.

Barely 15 months ahead of the next Quebec general election, the main takeaway of this by-election is that the CAQ is in electoral disarray, and the PQ clearly has the wind in its sails.

That year, although the CAQ candidate Eric Lefebvre won more than 50% of the vote, the Conservative candidate finished in second place with about 25%, compared to only 10, 9, and less than 4% for the PQ, Québec Solidaire, and Liberal candidates, respectively. That reality and the fact that Lefebvre successfully ran federally for the Conservatives in the federal riding of Richmond-Arthabaska, within the boundaries of which the Athabaska provincial riding is located gave hope to the provincial Conservatives. These factors help explain why their leader and former media personality Eric Duhaime decided to run in this by-election in the first place.

Considering the low popularity of Legault and of his party, there was a sense that the battle for Arthabaska would primarily be between the Conservative Duhaime and Boissonneault under the banner of the PQ, which is currently ahead in the polls. In such a context, this by-election was a test for the PQ as well as the CAQ, especially because this is the type of francophone riding in which the party should do well in a context in which the CAQ’s popularity has dramatically eroded since the 2022 general election.

In addition to their party’s strong performance in opinion polls, PQ supporters have been energized recently by the release of data suggesting that support for sovereignty has recently increased among young people. This trend, which might seem surprising in view of the rise of Canadian pride in Quebec early this year after the return of Donald Trump to the White House, is something to watch, especially if the PQ finds a way to maintain its lead in opinion polls until October 2026, when the next general election is scheduled.

If the PQ is the clear winner of Monday’s by-election and the CAQ its biggest loser, Duhaime’s second place is bad news for the Conservative Party of Quebec, which has failed once again to win a seat in the National Assembly. Another big loser of this by-election is Québec Solidaire, which won less than 2% of the votes, a truly abysmal performance, especially considering that the party had won more than 9% of the votes back in 2022.

Finally, although they more than doubled their score compared to their results in Arthabaska back in 2022, the Liberal Party of Quebec (LPQ) won fewer than 10% of the vote, which shows how much work they need to do to become competitive again among francophone voters under their new leader, former federal Liberal MP and cabinet minister Pablo Rodriguez. If they want to return to power, the once-formidable provincial Liberals now have 14 months to step up their game.

Daniel Béland is professor of political science and director (on leave) of the McGill Institute for the Study of Canada at McGill University.