OTTAWA — Voters in a number of ridings across the country will be asked to choose new federal representatives in the coming weeks and months as members of Parliament from four major parties take on diplomatic appointments, provincial races and retirement.

When a seat in the House of Commons becomes vacant, the prime minister must call an election between 11 and 180 days after the member’s resignation. A byelection campaign can be as short as 36 days or as long as 50 days, putting the date of voting somewhere between 47 days and seven months after the seat opens up.

Voters already went to the polls for byelections in the Quebec riding of Terrebonne, as well as University-Rosedale and Scarborough Southwest in Toronto.

Voters in three ridings will go to the polls Aug. 31:

Chicoutimi-Le Fjord

Richard Martel resigned from the House of Commons after accepting an appointment to the Senate from Prime Minister Mark Carney in July. He was first elected as a Conservative MP in a byelection in 2018.

Martel won a tight race in April 2025, beating the Bloc Québécois and Liberal candidates by about 1,500 votes.

Beaches-East York

Nate Erskine-Smith planned to run for the Ontario Liberal party leadership and had signalled for months that he would leave his federal post as a backbench Liberal MP and try to take on Premier Doug Ford in the next provincial race. But when he failed to lock up the party nomination to run in a byelection in Scarborough in May, those plans seemed to fall through. He stepped down in early July.

Erskine-Smith handily won the Beaches-East York riding in 2025 with 67 per cent of the vote.

North Vancouver-Capilano

Former Trudeau-era cabinet minister Jonathan Wilkinson resigned as a member of Parliament on June 19 after the close of the spring sitting. Prime Minister Mark Carney named him as Canada’s new ambassador to the European Union.

Wilkinson won his seat for a fourth time in 2025 with just shy of 60 per cent of the vote, his best result.

Here are the remaining ridings where byelections are expected soon:

Yorkton-Melville

Cathay Wagantall, who was elected as a Conservative MP in the east Saskatchewan riding in 2015, announced in late June that she would leave her seat at the end of the summer. She’s set her resignation for Aug. 31 and said the Conservatives already have chosen a candidate to stand in the byelection.

Wagantall won handily in the 2025 election with more than 77 per cent of the vote.

Rosemont-La Petite-Patrie

Alexandre Boulerice, who was the only NDP MP in Quebec, announced a move to provincial politics in late April. Boulerice quit the NDP caucus to sit as an Independent but has not yet resigned his seat. He said he will do that just before the start of the provincial election, which is expected to be called in late August, and will run for Québec solidaire.

Boulerice, who was first elected back in 2011, won the most recent election with 41 per cent of the vote, 10 points ahead of the Liberal candidate.

Saint-Hyacinthe-Bagot-Acton

Simon-Pierre Savard-Tremblay also quit his party’s caucus in the spring after announcing plans to stand in the Quebec provincial election. Savard-Tremblay left the Bloc Québécois benches on May 28, saying he would run under the Parti Québécois banner in the fall. He rejoined the Bloc caucus on June 19 and resigned from Parliament the same day.

Savard-Tremblay won the riding, a Bloc stronghold, in April 2025 by a 10-point margin.

Laurier-Sainte-Marie

Former environment minister Steven Guilbeault soured on the environmental policies of Prime Minister Mark Carney’s government last fall and stepped down as minister of Canadian identity and culture in late November. In May, he said he would resign as an MP, after Carney formalized a deal with Alberta that includes plans for a new oil pipeline. His office said he plans to resign on Aug. 28.

Guilbeault took more than 52 per cent of the vote in the 2025 election.

Brantford-Brant South

Larry Brock was the third Conservative to quit the House of Commons this summer. He announced in early August he’s planning to return to his former post in the Crown attorney’s office in Brantford, Ont. Brock said his last day as an MP will be Sept. 18, the week before the House of Commons resumes sitting.

Brock won his seat in 2025 by more than 7,400 votes.

Scarborough North

Shaun Chen was first elected as a Liberal MP in 2015 and served as a backbencher for more than a decade. He said on Aug. 10 he was planning to step down as a result of health issues he’s suffered since being in a vehicle accident while commuting to Ottawa last fall. Chen said his last day as an MP would be Aug. 15.

Chen won the 2025 election by a wide margin, with 63 per cent of the vote.

This report by The Canadian Press was first published Aug. 10, 2026.

Sarah Ritchie, The Canadian Press