Voters heading back to the polls in Terrebonne: here’s what you need to know

The Terrebonne byelection follows a one-vote election margin overturned by the Supreme Court.

It’s byelection day and voters in one Quebec riding are once again heading back to the polls.

The last time voters in the off-island Montreal suburb of Terrebonne cast their ballot, it was the closest race in the country: the Liberal candidate won by just a single vote over the Bloc Québécois opponent. But the results of the April 2025 general election in the riding were cancelled nearly 10 months later.

Two other byelections are also being held Monday in Toronto because the incumbents — the former Liberal MP for University—Rosedale, Chrystia Freeland, and the former Liberal MP for Scarborough Southwest, Bill Blair — left their seats vacant.

Those two ridings are both Liberal strongholds, so all eyes will really be on Terrebonne, where it’s a toss-up between the Bloc and the Liberals as Prime Minister Mark Carney tries to firm up a majority in the House of Commons.

Here’s what you need to know about the race in Terrebonne.

Why is there a byelection in Terrebonne?

Liberal candidate Tatiana Auguste won the election in Terrebonne, but her tenure didn’t last long. She secured 23,352 votes in the April 28, 2025 election, just one more vote than the Bloc’s Nathalie Sinclair-Desgagné.

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However, in February, the Supreme Court of Canada annulled the election results in the Quebec riding due to a clerical error on the return address on mail-in ballots supplied by Elections Canada.

Voter Emmanuelle Bossé had complained that her special ballot was returned to her mailbox due to the error, meaning her vote for Sinclair-Desgagné was never counted.

On March 8, Prime Minister Mark Carney called a byelection in all three ridings.

How late are polls open?

Polls open at 8:30 a.m. ET and will close at 8:30 p.m. ET.

Find your polling station by visiting the Elections Canada website.

• Watch special live coverage, CTV News Special: Federal Byelections 2026 hosted by Omar Sachedina and Vassy Kapelos, starting at 7 p.m. ET, streaming on CTVNews.ca, the CTV News App, CP24.com, the CP24 App, BNNBloomberg.ca, the BNN Bloomberg App, Crave, and broadcast on CTV News Channel, CP24 and BNN Bloomberg.

Record number of candidates on the ballot

The ballot will look a little different this time around. There is a record number of candidates in the Terrebonne byelection — 48 candidates, including 41 people without a party banner.

This is why Elections Canada has created an adapted ballot, and voters will need to write down the name of the candidate they are voting for on a blank space, replacing the standard bullet-point list used in previous elections. A list of candidates will be provided at the polling station.

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The protest group Longest Ballot Committee, which opposes Canada’s first-past-the-post system, has signed up several candidates in the byelection as it calls for electoral reform.

Elections Canada released a sample of the special ballot so voters know what to expect at the polls.

Though it’s a large number, 48 candidates is not a Canadian record. There were 214 candidates on the ballot in the byelection in Battle River-Crowfoot, which was won by Conservative Party leader Pierre Poilievre last August.

When will the result be known?

The race in Terrebonne will be closely watched because of how close the race was in 2025, but counting the adapted ballots will likely take longer than usual.

“The additional time needed is a result of needing to confirm the elector’s intent, and ensure everyone present, including witnesses, can see the marked ballot as the tallies are being recorded,” wrote Elections Canada spokesperson Matthew McKenna in an email to CTV News.

McKenna said he nonetheless expects the preliminary results to be known on election night.

McKenna said measures are being put in place to speed up the process. For the Battle River-Crowfoot byelection, Elections Canada started counting advance votes earlier in the day — two hours before polls closed — and hired additional poll workers to help with the counting.

The votes will be officially validated on April 15, a process that usually starts at noon and takes a few hours.

Until last year’s general election, the Bloc Québécois had held the seat in Terrebonne since 2015. Before that, it was mostly a Bloc riding, except during the 2011 NDP surge.

Who are the candidates?

Nathalie Sinclair-Desgagné, candidate for the Bloc Québécois

Nathalie Sinclair-Desgagné is campaigning on the slogan “Une voix qui compte” (“A vote that counts,” in English) — a fitting nod to the outcome of the 2025 vote. She was first elected to represent the riding of Terrebonne in the 2021 federal election. During her tenure, she served as the party’s shadow critic for public finances, COVID-19 pandemic programs, among other portfolios. She was born in 1988 and holds a degree in economics from McGill University and a master’s degree from the University of Oxford. Her career has taken her abroad to positions at the European Investment Bank in Luxembourg and at Pricewaterhouse Cooper in London. She returned to Quebec in 2017 and later worked as a senior economic adviser to the general management of the City of Montreal.

Tatiana Auguste, candidate for the Liberal Party of Canada

Tatiana Auguste was born in Port-au-Prince, Haiti in 2001 and immigrated to Canada with her family when she was seven, settling in Montreal-North. She has a bachelor’s degree in economics from Concordia University and later worked as an e-commerce consultant for the Fédération des chambres de commerce du Québec. Before entering politics, she served as political attaché to Emmanuel Dubourg, the Liberal MP for Bourassa.

Adrienne Charles, candidate for the Conservative Party of Canada

Adrienne Charles was a science teacher at the Centre de services scolaire des Affluents in Lanaudière. Prior to becoming a teacher, she spent nearly 25 years working in medical biology at a renowned pediatric hospital. She is also a published author, with two novels to her name.

Maxime Beaudouin, candidate for the New Democratic Party

Maxime Beaudouin is a long-time NDP activist from Laval. Since 2017, he has worked as a union adviser for the Alliance du personnel professionnel et technique de la santé et des services sociaux), a major health and social services sector union in Quebec. He has previously run as a candidate in Terrebonne in 2019 and 2025.

Benjamin Rankin, candidate for the Green Party of Canada

Benjamin Rankin has been an architect for more than 25 years after graduating from McGill University. He works predominantly in health care and educational projects.

What were the results in 2025?

• Tatiana Auguste (Liberal Party of Canada): 23,352
• Nathalie Sinclair-Desgagné (Bloc Québécois): 23,351
• Adrienne Charles (Conservative Party of Canada): 10,961
• Maxime Beaudoin (New Democratic Party): 1,556
• Benjamin Rankin (Green Party of Canada): 630

By the numbers

• Number of eligible voters in Terrebonne: 91,232
• Population in Terrebonne riding: 113,797 people
• Number of Terrebonne electors who cast a ballot in 2025: 60,278
• Voter turnout in Terrebonne 2025: 66 per cent

With files from CTV News’ Anton Koschany