Upcoming by-elections could give Mark Carney’s Liberals a majority — Here’s how it works

Prime Minister Mark Carney recently called three by-elections for April 13, and the results could have an impact on both the makeup of Parliament and how long it lasts.

Here’s a primer on how things could change.

IN CASE YOU MISSED IT: Carney is now 2 seats from a majority after another floor crossing, with 3 more up for grabs

Where are the by-elections?

The votes are in two Liberal stronghold seats in the Toronto area and one contested riding in Quebec, north of Montreal.

Voters in Scarborough Southwest and University—Rosedale will choose new members of Parliament after two former Liberal cabinet ministers stepped down.

Bill Blair left his seat to become Canada’s high commissioner to the U.K., while Chrystia Freeland has a number of new roles, including as economic adviser to the Ukrainian president and CEO of the Rhodes Trust.

Observers expect the Liberals to hold both ridings. The third by-election is the one with the most intrigue.

The race in Terrebonne last April was the closest in the country — the Liberals won by a single vote on election night. A court challenge was filed after it was found that Elections Canada put an incorrect return address on some mail-in ballots, which were never counted.

The Supreme Court of Canada invalidated the result in February and the vote is being redone.

Polling aggregator 338 Canada says Terrebonne, which has voted Bloc Québécois in recent elections, is a toss-up between the Liberals and Bloc.

Bloc Québécois Leader Yves-François Blanchet, right, arrives for a news conference alongside Terrebonne by-election candidate Nathalie Sinclair-Desgagne in Terrebonne, Que., Thursday, Feb. 26, 2026. Graham Hughes | The Canadian Press

Why is Terrebonne so important to the Liberals?

If the Liberals hold the two Toronto seats, they’ll have 172 MPs and a majority in the House of Commons.

But the House Speaker is Liberal MP Francis Scarpaleggia and the Speaker only votes in the event of a tie. A government with 172 seats needs at least one opposition member to vote with them or abstain from voting to pass legislation.

If the Liberals win in Terrebonne, they’ll have that critical extra vote.

Prime Minister Mark Carney, right, and Terrebonne candidate Tatiana Auguste, walk in Terrebonne, Que., on Tuesday, Feb. 17, 2026. Christinne Muschi | The Canadian Press

Why is this situation so unusual?

Prime Minister Mark Carney’s team has been trying to do something that hasn’t been done in living memory — turn a minority government into a majority by recruiting members from opposition parties.

It started with Nova Scotia MP Chris d’Entremont, who crossed the floor in November after the government introduced its budget. Ontario MP Michael Ma made the same trek from the Conservative side of the House just before Christmas.

It took several months to seal the deal with Alberta Conservative Matt Jeneroux, who joined Carney’s team in February, and Nunavut MP Lori Idlout, who left the dwindling NDP bench earlier this month.

The Conservatives have slammed these moves and have accused Carney of cutting “shady backroom deals” and creating an “undemocratic” majority. They’ve stopped short of calling for rule changes to prevent floor-crossings in the future.

Prime Minister Mark Carney walks with Nunavut MP Lori Idlout, who crossed the floor from the NDP to the Liberals, as they make their way to a meeting of the Liberal caucus on Parliament Hill in Ottawa, on Wednesday, March 11, 2026.Justin Tang | The Canadian Press

What would change in the House of Commons if the Liberals get a majority?

The biggest change is about confidence votes.

Canadians have elected minority Liberal governments in three elections since 2019. In order to stay in power, minority governments have to survive tests of Parliament’s confidence in the form of votes on throne speeches, budgets and non-confidence measures.

A majority government can breathe a little easier on those key votes.

But Éric-Antoine Menard, vice-president and head of Quebec operations at North Star Public Affairs, said 172 is “not a magical number.”

Majority governments typically also hold majorities on committees — places where the opposition can really slow down legislation.

MPs unanimously agreed in June to set up committees for the rest of this Parliament made up of five Liberals, four Conservatives and one member from the Bloc Québécois.

The Liberals don’t automatically get another seat on committees if they get a majority, and committees can’t be reset by proroguing Parliament and starting a new session with a throne speech.

If the government wants more control over committees, it will need to either get the opposition parties to agree to make a change that limits their power, or amend the Standing Orders.

Menard said he thinks that’s a fight the Liberals don’t want.

“There’s there’s no particular rush that I see on the government’s part to just take control of the House of Commons and disrupt the mood there,” he said.

“The mood is generally positive. The government is riding high in the polls, it’s moving its agenda by working with some of the other parties, which I think currently Canadians kind of appreciate.”

Susan Smith, principal and co-founder of BlueSky Strategy Group, disagrees.

“I think making sure that the House of Commons functions more smoothly and that there’s less shenanigans from the opposition in committee will be really important,” she said.

What happens next?

As Menard pointed out, there could be more by-elections to come — so even if the Liberals eke out a majority, they may not be able to keep it long.

Liberal MP Nate Erskine-Smith is exploring a run for the Ontario Liberal leadership and plans to vacate his seat in Beaches—East York to run in a provincial by-election. It’s been rumoured for months that North Vancouver—Capilano MP Jonathan Wilkinson may be looking for a diplomatic posting.

There have also been media reports that NDP MP Alexandre Boulerice is pondering a jump to Quebec provincial politics.

Floor-crossing rumours continue to circulate on Parliament Hill. In short, the numbers are still unstable.

Menard said a narrow majority government also presents a challenge for Carney, who would have to ensure his entire caucus — which now includes one former New Democrat and several former Tory MPs — is on the same page.

“You do not know how these people are going to react on an issue-to-issue basis,” he said.

What does all of this mean for the timing of the next election?

A majority government could stay in power for another three years. It could also call an early election.

Most major polls suggest the Liberals have a wide lead and Carney is significantly more popular than Conservative Leader Pierre Poilievre.

Smith said that’s the kind of thing every government keeps its eye on as it weighs whether to send Canadians to the polls.

“Right now, no, there aren’t Canadians that are saying we need an election,” she said.

But if things are still uncertain geopolitically in the next few months, she said, “I think it’s something that isn’t off the table yet. It’s just not on tonight’s dinner table.”

This report by The Canadian Press was first published March 21 2026.