Founder of Nanos Research Nik Nanos breaks down the state of play for the parties and the leaders that could bring the Liberals closer to a majority.

Canadians in three ridings are heading to the polls today. How they vote could determine if Prime Minister Mark Carney’s Liberals secure a majority government by the end of the night.

Nearly a year after last April’s minority government victory and on the heels of courting five opposition MPs to cross the floor, the Liberals’ control over Parliament is on the verge of stabilizing, depending on the results of three byelections.

Up for grabs are two Ontario Liberal strongholds where former senior cabinet ministers Chrystia Freeland and Bill Blair resigned: University-Rosedale and Scarborough Southwest, respectively.

Should Carney also pick up the hotly contested Terrebonne, Que. riding – after last year’s election result was invalidated by the Supreme Court – that would mean the Liberals could be sitting at 174 seats come tomorrow.

In Freeland’s old University-Rosedale riding, family doctor Danielle Martin is facing off against Conservative candidate Don Hodgson and New Democrat Serena Purdy.

In Blair’s former Scarborough Southwest riding, former Ontario NDP deputy leader Doly Begum is hoping to beat Conservative candidate Diana Filipova and NDP candidate Fatima Shaban.

In hotly-contested Terrebonne, Que., Liberal candidate Tatiana Auguste is facing off against Bloc Quebecois candidate Nathalie Sinclair-Desgagné – who held the seat from 2021 until last year’s election – and Conservative hopeful Adrienne Charles.

CTV National News: Byelections loom as key Quebec riding draws national attention The Liberals are eying wins in two ridings, but Terrebonne remains a wildcard. Annie Bergeron-Oliver explains why this Quebec race is drawing national focus.

This seat was vacated earlier this year, after the razor-thin 2025 election result was invalidated by the Supreme Court. With 48 people on the ballot in Monday’s by-election – due to the “longest ballot” protest effort – Elections Canada is using write-in ballots.

Polls are open in these ridings between 8:30 a.m. and 8:30 p.m. ET.

Floor-crossers played a role in nearing majority

The Liberals have hovered around the 172-seat threshold for a majority government since the 2025 general election, when they came up just three ridings short, winning 169 seats.

After months of working across party lines to garner enough support to pass bills, and those two aforementioned Trudeau-era cabinet ministers resigning, a series of floor-crossings started to make the math easier for Carney’s minority government.

In about as many months, Carney attracted five opposition MPs to cross the floor, putting his party at 171 seats as of last Wednesday when Marilyn Gladu became the newest Liberal recruit.

The standings in the House of Commons going into tonight’s by-elections are: Liberals 171 seats, Conservatives 140 seats, Bloc Quebecois 22 seats, NDP six seats, Greens one seat, and of course the three vacancies. Combined, the opposition parties hold 169 seats.

‘Persistent indications’ in Parliament that there are more floor crossings ahead, Tom Mulcair says CTV News’ Political Commentator Tom Mulcair says Tories are ‘nervous’ about Poilievre not being able to win an election, hence the recent floor crossings.

If the Liberals win just one riding, they would have a majority on paper, but would need Liberal MP and House Speaker Francis Scarpaleggia to cast a vote in their favour in the case of a tie. Any additional victories this evening would strengthen their ability to control parliamentary outcomes.

Carney has already insisted that he is not considering proroguing Parliament if he secures a majority. He wouldn’t need to, in order to take control of House committees, which are widely considered where the bulk of work in the Commons can be accomplished.

“We are absolutely focused on working with Parliament, getting legislation through Parliament, adjusting legislation where it needs to be, where it’s better informed by the discussions in Parliament,” Carney said in late March.

This is a developing story.