A federal by-election will be held in the Quebec federal electoral district of Laurier—Sainte-Marie following the resignation of Liberal member of Parliament (MP) Steven Guilbeault on August 28, 2026. Elections Canada received official notice of the vacancy on August 31. The date of the by-election must be announced between September 11, 2026, and February 27, 2027, with October 19, 2026, being the earliest possible election date.

Background Guilbeault, an environmental activist before entering federal politics, was first elected to the House of Commons in the 2019 Canadian federal election. He served as Minister of Canadian Heritage from 2019 to 2021 and as Minister of Environment and Climate Change from 2021 to 2025. He was re-elected in 2021 and 2025.

In the 2025 federal election, Guilbeault was re-elected with 27,286 votes, or 52.1 per cent of the vote. New Democratic Party (NDP) candidate Nimâ Machouf finished second with 9,856 votes, or 18.8 per cent, followed by Bloc Québécois candidate Emmanuel Lapierre with 8,079 votes, or 15.4 per cent.

On May 27, 2026, Guilbeault announced that he would resign from Parliament later that summer, saying that he wanted to continue his work on environmental protection and climate change outside elected politics. Guilbeault had resigned from the federal cabinet in November 2025 over the government's agreement with Alberta concerning a proposed oil pipeline and changes to federal climate policy.

Guilbeault's office subsequently confirmed that he would leave Parliament on August 28. On August 31, Chief Electoral Officer Stéphane Perrault received official notice from the Speaker of the House of Commons that the seat was vacant. Under the timetable announced by Elections Canada, the by-election must be called between September 11, 2026, and February 27, 2027. Once called, it must be held on a Monday at least 36 days and no more than 50 days later. The earliest possible date for the by-election is therefore October 19, 2026.

Guilbeault's departure created the second pending federal by-election on the island of Montreal, alongside Rosemont—La Petite-Patrie, where former NDP MP Alexandre Boulerice also left federal politics to seek election provincially.

Laurier—Sainte-Marie was represented from 1990 to 2011 by Gilles Duceppe, who subsequently became leader of the Bloc Québécois. He was defeated in 2011 by the NDP's Hélène Laverdière, who represented the riding until Guilbeault defeated her in 2019. Following Guilbeault's announcement, Bloc Québécois leader Yves-François Blanchet said that his party expected to be "highly competitive" in the riding.

Candidates New Democratic Party On July 16, 2026, the NDP nominated epidemiologist Nimâ Machouf as its candidate. Machouf had previously been the party's candidate in Laurier—Sainte-Marie in the 2019, 2021 and 2025 federal elections, finishing second on each occasion.

Result

Previous result

See also

By-elections to the 45th Canadian Parliament

Notes

References