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Supreme Court Nullifies Terrebonne Election Over Mail-Ballot Error
By Drooid · · How we work
Supreme Court Overturns the April 28, 2025 Result
On February 13, the Supreme Court of Canada issued a split-decision (6-3) that annulled the federal election held in the Montreal-area riding of Terrebonne on April 28, 2025. The Court found that Elections Canada’s failure to correct a known postal-code mistake on special-ballot envelopes constituted a “serious administrative error” capable of undermining the integrity of the electoral process. Justice Mahmud Jamal, writing for the majority, emphasized that allowing an election to be decided by a “known and correctable administrative error” would erode public trust.
Background of the Mail-Ballot Mistake
During the 2025 campaign, Elections Canada printed return envelopes for about 115 local mail-in special ballots with an incorrect postal code for its Terrebonne office. An employee discovered the error more than three weeks before voting day but did not inform supervisors. Of the 115 ballots, 85 arrived on time and were counted, five arrived late, and 16 were never returned. One voter, Emmanuelle Bosse, reported that her ballot was returned to her own mailbox because of the faulty label, preventing her vote from being counted. The judicial recount showed Liberal candidate Tatiana Auguste ahead of Bloc Québécois incumbent Nathalie Sinclair-Desgagné by a single vote (23,352 vs 23,351).
Court Reasoning and Vote Impact
The majority held that the error was known, remained uncorrected, and directly affected the sole deciding vote. The minority warned that the low threshold could invite future challenges, but the majority stressed that the legal standard for overturning elections remains stringent.
Elections Canada’s Response
Elections Canada announced a review of its special-ballot process, noting that Chief Electoral Officer Stéphane Perrault will determine any further actions. The agency reported that it has already implemented 13 recommendations, including peer review of mail-return labels, stronger monitoring of ballot-return rates, data-system upgrades, and automated printing of return-address labels to reduce manual errors.
Implications for Canadian Electoral Law
The ruling clarifies that Section 524 of the Canada Elections Act can be invoked when a preventable administrative failure deprives a voter of a counted ballot, even if the error is not fraudulent. By applying this standard to a one-vote margin, the Court signals that electoral officials must promptly correct known logistical mistakes, reinforcing safeguards against inadvertent disenfranchisement while maintaining a high bar to prevent frivolous challenges.