The federal Liberals achieved a sweeping victory by winning all three byelections held on Monday night in Ontario and Quebec, solidifying Prime Minister Mark Carney's position with a majority government. This win enhances their total to 174 seats in the House of Commons.
In Ontario, the byelection in the University-Rosedale riding was promptly called for Liberal candidate Danielle Martin. Likewise, Doly Begum secured the Scarborough Southwest riding for the Liberals. However, the results in the Terrebonne riding were closely contested. With 100 percent of the polls counted, Liberal candidate Tatiana Auguste emerged victorious over Bloc Québécois' Nathalie Sinclair-Desgagné by a narrow margin of 731 votes.
The successes in these byelections are pivotal for the Liberals, as Martin’s win alone granted them their 172-seat majority in the federal government, while the additional wins in Scarborough Southwest and Terrebonne pushed their total to 174. In her victory speech, Martin emphasized the mandate given to the Liberal Party, saying, "As of tonight, Mark Carney and our entire incredible Liberal team have earned an even more powerful mandate to continue building a better Canada." She outlined key issues that the government must prioritize, including housing, affordability, healthcare, climate change, and infrastructure.
The University-Rosedale seat was vacated following Chrystia Freeland's resignation in January, which she undertook to become an adviser to Ukraine and the CEO of the Rhodes Trust at Oxford University. In this byelection, Martin faced competition from various candidates: Serena Purdy, representing the NDP; Don Hodgson, a Conservative business owner; and Andrew Massey, a Green Party writer and editor. Ultimately, Martin secured 64 percent of the votes, while Purdy garnered 18 percent.
In Scarborough Southwest, the seat became available after Bill Blair resigned in February to assume the role of Canada’s high commissioner to the United Kingdom. Begum, who previously served as the deputy leader of the Ontario NDP, won decisively, capturing nearly 70 percent of the unofficial vote total. In her victory speech, Begum expressed gratitude to the supporters who helped her during the campaign. She mentioned her post-election conversation with Prime Minister Carney, where he congratulated her and invited her to attend caucus meetings.
The Conservative candidate, Diana Filipova, and the NDP candidate, Fatima Shaban, trailed Begum, with Filipova receiving over 18 percent of the vote. The voter turnout in Scarborough Southwest was noted to be around 33.5 percent of eligible voters, while in University-Rosedale it was just over 32 percent.
Turning to the byelection in Terrebonne, it followed a prior controversy regarding a mail-in ballot from the previous year. Initially, Auguste was declared the winner in April 2025, before the results were overturned in favor of Sinclair-Desgagné after a validation process. However, a judicial recount on May 10, 2025, later confirmed that the Liberals had won by a single vote.
The Liberal Party's majority positioning was propelled by five floor crossings, including four MPs from the Conservative Party who switched allegiance to the Liberals between November 2025 and April 2026. This included noted MPs like Marilyn Gladu, Chris d’Entremont, Michael Ma, and Matt Jeneroux. Additionally, NDP MP Lori Idlout defected in March.
