Sinclair-Desgagné v. Canada (Chief Electoral Officer)

Decided: 2026-09-18. Docket: 42076. Citation: 2026 SCC 31 (CanLII). Procedure — Elections — Contested election application — Canada Elections Act, ss. 524(1)(b), 531(2) — Whether postal code error and failure to correct constituted an irregularity affecting the result — Opitz v. Wrzesnewskyj three-step test applied — Serious administrative error capable of undermining franchise found — Election in electoral district annulled | Statutory interpretation — Modern approach — Associated words rule — Canada Elections Act, s. 524(1)(b) — Whether “irregularity” includes serious administrative error without dishonest intent — Noscitur a sociis applied to “irregularities, fraud or corrupt or illegal practices” — Serious administrative error honest and unintentional included — Appeal allowed | Proced