The Parti Québécois sailed to a third-straight Quebec byelection win on Monday, cementing the sovereigntist party's momentum ahead of the 2026 provincial election and dealing a crushing blow to Premier François Legault's governing party.
Former journalist Alex Boissonneault handily defeated Quebec Conservative Leader Éric Duhaime in the Arthabaska riding, flipping a seat that Legault's Coalition Avenir Quebec has held since 2012.
While polls had suggested Boissonneault and Duhaime were neck-and-neck, the PQ candidate captured over 46 per cent of the vote, compared to just over 35 per cent for Duhaime.
"Tonight, we have achieved an extraordinary feat," Boissonneault told supporters. "We have just reclaimed the magnificent corner of the country that is ours."
The sovereigntist party also won in Jean-Talon in 2023 and Terrebonne earlier this year. The party sits fourth in seat count in the province's legislature, but has been leading in the polls for the better part of two years.
Boissonneault, who was born and grew up in the riding, campaigned on a promise to restore a "broken social contract" that sees Quebecers pay high taxes without getting enough in return.
Parti Québécois Leader Paul St-Pierre Plamondon called the victory "highly significant," noting it was the party's first win in the riding in 27 years.
"It's also a very significant victory because we're adding another key piece, another pillar of what could constitute a team capable of replacing the CAQ and forming a solid government in 2026," he told a jubilant watch party in the riding midway between Montreal and Quebec City.
Supporters at the Parti Québécois event exploded with joy when the results were announced shortly before 10 p.m., waving blue-and-white Quebec flags. They chanted "Alex! Alex!" and, during St-Pierre Plamondon's speech, "Quebec! A country!"
St-Pierre Plamondon, who has promised to hold a third independence vote by 2030 if his party forms government, said the result is also "a defeat for parties who had the fear of a referendum as their only argument."
Duhaime had been hoping to win a first legislature seat for the party he revived from obscurity when he took over as leader in 2021. During the campaign, he advocated for scrapping electric vehicle mandates and the carbon-pricing system as well as increased privatization in health care.
Duhaime said Monday that the byelection was a missed opportunity to correct what he has termed the "distortion" of the 2022 election that saw his party capture 13 per cent of the vote but no seats.
"There are more than one out of eight Quebecers who will have zero out of 125 representatives in the worst democratic distortion in the history of Quebec," he said. "Today it wasn’t just the Conservative Party of Quebec that lost, it’s Quebec democracy."
However, he noted that his party started "almost from zero" four years ago. "We're the party that progresses all the time," he said, promising to redouble efforts ahead of the 2026 election.
Monday's defeat was also a bitter loss for the governing Coalition Avenir Québec, which lost a riding it has held since 2012 with a distant fourth-place finish.
In a speech delivered before the final result was announced, the premier placed the blame on himself. “I take full responsibility for today's defeat,” he told supporters.
Legault acknowledged voters’ unhappiness with his government, citing the disastrous rollout of an online platform for the auto insurance board, a massive investment in an electric battery plant whose future is uncertain, and a failure to improve the efficiency of public services.
“I think the people of Arthabaska-L’Erable were the spokespersons for all Quebecers,” he said in a speech alongside candidate Keven Brasseur. “And they sent us a very clear, very direct message: they are disappointed. Quebecers are disappointed with our government.”
Legault indicated he still planned to run for reelection next year, telling supporters he felt his experience was still needed to help reshape Quebec’s economy.
The Quebec Liberals, who have seen a bump in support under new leader Pablo Rodriguez, climbed to third after finishing fifth in the riding in the 2022 election.
The byelection was triggered after Coalition Avenir Québec member Éric Lefebvre resigned to run successfully for the Conservative Party of Canada in the last federal election.
This report by The Canadian Press was first published Aug. 11, 2025.
Thomas Laberge and Morgan Lowrie, The Canadian Press
