Supreme Court annuls single-vote win in Terrebonne riding, vacating seat
Bloc candidate Nathalie Sinclair-Desgagné has won her appeal of the single-vote loss.
Author of the article:Montreal Gazette
Published Feb 13, 2026 • Last updated 16 hours ago • 4 minute read
Liberal Tatiana Auguste, left, has lost her seat as MP for Terrebonne after the Supreme Court sided with a challenge by Bloc Québécois candidate Nathalie Sinclair-Desgagné, right, who lost the election by one vote.
Liberal Tatiana Auguste, left, has lost her seat as MP for Terrebonne after the Supreme Court sided with a challenge by Bloc Québécois candidate Nathalie Sinclair-Desgagné, right, who lost the election by one vote. Photos: Liberal Party of Canada, Bloc Québécois
The Supreme Court of Canada on Friday granted an appeal by a Bloc Québécois candidate who lost the federal election in Terrebonne riding by a single vote, vacating the seat and requiring a byelection to determine the winner.
Liberal Tatiana Auguste won the seat in the April 28 general election after a judicial recount, but Bloc Québécois candidate Nathalie Sinclair-Desgagné appealed to the courts, who found in Auguste’s favour. Auguste has been sitting as the MP for the riding since she was sworn in on May 22.
Elections Canada said Friday a byelection will be called within 180 days to fill the seat and it is ready to administer that byelection.
Sinclair-Desgagné let out a long sigh of relief shortly after she heard the ruling, announced from the bench following a hearing earlier on Friday. Chief Justice Richard Wagner simply announced the decision reflected the opinion of the majority of the nine justices, and the reasons would be specified in a written decision to be released later.
“The Supreme Court decided today that every vote counts, that one person’s vote is not worth more than another person’s vote, and that, in the event of a tie, the election must be rerun,” Sinclair-Desgagné said outside the courtroom, adding she was reassured by this “victory for democracy.”
“Until today, there was someone sitting who, nevertheless, lacked the legitimacy to do so. Fortunately, that has been rectified today,” she declared.
In a written statement, Bloc Québécois president Suzanne Proulx praised her candidate’s long battle and the fact the country’s highest court confirmed through its decision the right to vote is fundamental to a democracy. The party is now calling for the byelection to be called “without delay.”
As for the Liberals, their spokesperson, Matteo Rossi, stated the party respects “the decision and the institutions that reinforce the great confidence Canadians have in the integrity of our electoral process.” He declared his party is ready to fight again in Terrebonne.
One-vote victory
On election night, the riding’s lead swung back and forth, and final preliminary results showed a narrow 25-vote win for Auguste. But when the tallies were validated, they showed a 44-vote lead for Sinclair-Desgagné, who was the incumbent MP.
A judicial recount followed, which flipped the result back to Auguste by a single vote.
The results were complicated after it was revealed an error by an Elections Canada employee put the wrong postal code on some special mail-in ballots, and one voter, Emmanuelle Bossé, whose ballot was returned to her after election day revealed she had voted for the Bloc.
Sworn statements filed in the case show an election employee discovered he had mistakenly printed his own postal code on several special ballots about three weeks before election day. He estimated a minimum of 40 envelopes had gone out with the wrong postal code. The employee said he didn’t deem it necessary to inform his superior of the mistake because the number of ballots returned to the elections office wasn’t higher than during past elections.
Quebec Superior Court Justice Éric Dufour ruled in October the postal code error does not constitute an irregularity as defined under federal electoral law. “It is a simple human error, which sometimes occurs in general elections, committed inadvertently and without any dishonest or malicious intent,” the judge wrote.
Sinclair-Desgagné appealed to the Supreme Court, saying the Superior Court decision “contains several errors of fact as well as an interpretation of the law and jurisprudence that invites an appeal.”
The issue before the Supreme Court was whether this error constitutes an “irregularity” under the law.
During Friday’s oral hearing, Supreme Court justices peppered Auguste’s lawyers with questions, repeatedly interrupting them.
Auguste’s legal team, led by lawyer Marc-Étienne Vien, argued the voter whose mail-in ballot was returned was “not prevented from voting.”
“Hold on a minute,” Chief Justice Richard Wagner said. “The purpose of the law is to promote public participation at a time in history when institutions are under strain.”
Several other interruptions from judges followed.
“It seems to me the responsibility is totally clear,” Justice Malcolm Rowe said, adding responsibility for the error is on Elections Canada, not the elector.
Vien said invalidating the election required “a serious error … associated with fraud.” He added lowering the threshold for challenging an election could create “a problematic precedent.”
“This isn’t about a breach of procedures or Elections Canada’s responsibilities,” Vien said. “It’s simply a routine, clerical error.”
In the end, the court agreed with Sinclair-Desgagné’s legal team an irregularity does not require intentional or bad faith acts.
The vacancy reduces the Liberal Party’s seat count to 168, four short of a majority. Two other seats are vacant, University—Rosedale and Scarborough Southwest in Toronto, vacated by Chrystia Freeland and Bill Blair, respectively, since the beginning of 2026.
La Presse Canadienne contributed to this report.
Bloc candidate Nathalie Sinclair-Desgagné has won her appeal of the single-vote loss.
torontosun.com