Nathalie Sinclair-Desgagné v. Directeur général des élections du Canada, Directeur du scrutin de la circonscription de Terrebonne, et al. (42076)

(Confidentiality order)Following the Canadian general election held on April 28, 2025, and the subsequent judicial recount, the respondent Tatiana Auguste became a member of Parliament for the electoral district of Terrebonne. Only one vote in her favour separated her from her closest rival, the appellant, Nathalie Sinclair-Desgagné. One voter then notified the media that her special ballot, mailed within the prescribed time, had been returned to her after the polling day, marked [translation] “Moved or unknown – return to sender”. In fact, there was an error in the postal code that the returning officer placed on the prepaid envelope sent to the voter in that the last three characters of the postal code were for somewhere other than the polling station. But that voter maintained that she voted for Ms. Sinclair-Desgagné.The Superior Court found that there was no irregularity within the meaning of s. 524(1)(b) of the Canada Elections Act. It therefore dismissed the application to contest the election filed by Ms. Sinclair-Desgagné. Argued Date 2026-02-13 Keywords Elections — Application to contest election — Irregularity — Allegations of irregularities that affected result of election made by candidate defeated by single vote in federal election — Whether trial judge erred in interpretation of notion of irregularity — Whether trial judge erred in determination of consequences of irregularity on integrity of electoral system — Whether trial judge erred in imposing burden much greater than that under Canada Elections Act on voter — Canada Elections Act, S.C. 2000, c. 9, ss. 524(1)b), 531(2). Notes (Quebec) (Civil) (As of Right) (Publication ban in case) (Sealing order) (Certain information not available to the public) Language Floor Audio Disclaimers This podcast is created as a public service to promote public access and awareness of the workings of Canada's highest court. It is not affiliated with or endorsed by the Court. The original version of this hearing may be found on the Supreme Court of Canada's website. The above case summary was prepared by the Office of the Registrar of the Supreme Court of Canada (Law Branch).