Case information
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42076
Nathalie Sinclair-Desgagné v. Attorney General of Canada, et al.
(Quebec) (Civil) (As of Right)
Docket
Judgments on applications for leave to appeal are rendered by the Court, but are not necessarily unanimous.
| Date | Proceeding | Filed By (if applicable) |
|---|---|---|
| 2025-12-08 |
Motion to extend time, (Book Form), to serve and file extended record Missing: - Proof of service on Maxime Beaudoin's counsel, Incomplete, (Printed version filed on 2025-12-10) |
Nathalie Sinclair-Desgagné |
| 2025-12-08 | Certificate of counsel (attesting to record), (Letter Form), 24A, (Printed version filed on 2025-12-10) | Nathalie Sinclair-Desgagné |
| 2025-12-08 | Certificate (on limitations to public access), (Letter Form), 23B, (Printed version filed on 2025-12-10) | Nathalie Sinclair-Desgagné |
| 2025-12-08 |
Appellant's record, (Book Form), Missing: -Proof of service on Maxime Beaudoin's counsel, Incomplete, (Printed version filed on 2025-12-10) |
Nathalie Sinclair-Desgagné |
| 2025-12-08 |
Appellant's factum, (Book Form), Missing: -Proof of service on Maxime Beaudoin's counsel, Incomplete, (Printed version filed on 2025-12-10) |
Nathalie Sinclair-Desgagné |
| 2025-12-05 | Notice of hearing sent to parties | |
| 2025-12-04 | Appeal hearing scheduled, 2026-02-13 | |
| 2025-12-02 | Order on motion to directions, by THE CHIEF JUSTICE | |
| 2025-12-02 |
Decision on motion for directions, CJ, UPON APPLICATION by the appellant, Nathalie Sinclair Desgagné, for an order for directions to set the date of the hearing of the appeal, abridge the time limits provided for in the Rules of the Supreme Court of Canada, establish a schedule for the filing of the appeal documents and dispense with the printing of certain documents; AND THE MATERIAL FILED having been read; IT IS HEREBY ORDERED THAT: The motion is granted in part. The appeal shall be heard on February 13, 2026. Documents shall be served and filed in accordance with the following schedule: (1) The factum, record and book of authorities, if any, of the appellant, Nathalie Sinclair Desgagné, shall be served and filed on or before December 8, 2025. (2) The factum on cross appeal and book of authorities, if any, of the respondent Tatiana Auguste shall be served and filed on or before December 22, 2025. (3) The motion to adduce new evidence shall be served and filed on or before December 22, 2025. Responses to this motion, if any, shall be served and filed on or before January 9, 2026. Reply to the reponses, if any, shall be served and filed on or before January 13, 2026. (4) The factums, records and books of authorities, if any, of the other respondents on appeal and on cross appeal shall be served and filed on or before January 26, 2026. (5) The appellant’s factum on conditional cross appeal shall be served and filed on or before February 2, 2026. (6) The motions for intervention in this appeal pursuant to Rule 55 of the Rules of the Supreme Court of Canada shall be served and filed on or before December 29, 2025. (7) All responses to the motions for intervention, if any, shall be served and filed on or before January 6, 2026. (8) All replies to the responses to the motions for intervention, if any, shall be served and filed on or before January 8, 2026. (9) If leave to intervene is granted, the factums and books of authories, if any, of the interveners shall be served and filed on or before January 30, 2026. It is not necessary to consider the application to dispense with the printing of documents forming part of a record filed pursuant to Rule 38.1 of the Rules of the Supreme Court of Canada. Judgment accordingly |
|
| 2025-12-02 | Submission of motion for directions, CJ | |
| 2025-11-17 | Correspondence received from, Re: appointment of correspondent | Adrienne Charles |
| 2025-11-17 | Certificate (on limitations to public access), 23A &23B | Adrienne Charles |
| 2025-11-17 | Response to motion for directions, (Letter Form), Completed on: 2025-11-18 | Adrienne Charles |
| 2025-11-17 | Response to motion for directions, (Letter Form), Completed on: 2025-11-18 | Directeur général des élections du Canada, Directeur du scrutin de la circonscription de Terrebonne |
| 2025-11-14 | Response to motion for directions, Completed on: 2025-11-17 | Tatiana Auguste |
| 2025-11-13 | Motion for directions, (Book Form), Completed on: 2025-11-17 | Nathalie Sinclair-Desgagné |
| 2025-11-07 |
Certificate (on limitations to public access), (Letter Form), (Included in the notice of appeal), 23B -Need an Amended version (rec'd 2025-11-07), (Printed version filed on 2025-11-07) |
Nathalie Sinclair-Desgagné |
| 2025-11-06 |
Certificate (on limitations to public access), 23B -Need amended 23B (rec'd 2025-11-10), (Electronic version filed on 2025-11-06) |
Tatiana Auguste |
| 2025-11-04 |
Correspondence received from, (Letter Form), the appellant on cross-appeal about cross-appeal being conditional. Missing: -Proof of service (rec'd 2025-11-05), (Printed version filed on 2025-11-06) |
Tatiana Auguste |
| 2025-11-04 |
Certificate (on limitations to public access), (Letter Form), 23A Amended version filed on 2025-11-10, (Printed version filed on 2025-11-06) |
Tatiana Auguste |
| 2025-11-04 |
Notice of cross appeal, (Book Form), Missing: -Proof of service (rec'd 2025-11-05) -23B (rec'd 2025-11-05) -Amended 23B , Incomplete, (Printed version filed on 2025-11-06) |
Tatiana Auguste |
| 2025-11-04 | Letter acknowledging receipt of a notice of appeal, File opened | |
| 2025-11-03 |
Certificate (on limitations to public access), (Letter Form), (Included in the notice of appeal), 23A Amended version filed on 2025-11-07, (Printed version filed on 2025-11-04) |
Nathalie Sinclair-Desgagné |
| 2025-11-03 |
Notice of appeal, (Book Form), Missing: -All respondent's contact information (rec'd 2025-11-04) -Amended cover page (rec'd 2025-11-07) -Proof of service on all parties (rec'd 2025-11-07) -Amended 23B (rec'd 2025-11-1), Completed on: 2025-11-12, (Printed version filed on 2025-11-07) |
Nathalie Sinclair-Desgagné |
Parties
Please note that in the case of closed files, the “Status” column reflects the status of the parties at the time of the proceedings. For more information about the proceedings and about the dates when the file was open, please consult the docket of the case in question.
Main parties
| Name | Role | Status |
|---|---|---|
| Sinclair-Desgagné, Nathalie | Appellant / Respondent on cross-appeal | Active |
v.
| Name | Role | Status |
|---|---|---|
| Attorney General of Canada | Respondent / Respondent on cross-appeal | Active |
| Directeur général des élections du Canada, Directeur du scrutin de la circonscription de Terrebonne | Respondent / Respondent on cross-appeal | Active |
| Auguste, Tatiana | Respondent / Appellant on cross-appeal | Active |
| Beaudoin, Maxime | Respondent / Respondent on cross-appeal | Active |
| Cantore, Maria | Respondent / Respondent on cross-appeal | Active |
| Charles, Adrienne | Respondent / Respondent on cross-appeal | Active |
| Rankin, Benjamin | Respondent / Respondent on cross-appeal | Active |
Counsel
Party: Sinclair-Desgagné, Nathalie
Counsel
Niall Clapham Ricardo
Julius H. Grey
Sasha Fortin
4920, boul. de Maisonneuve O., Bureau 305
Westmount, Quebec
H3Z 1N1
Telephone: (514) 288-6180
FAX: (514) 288-8908
Email: agagnon@greycasgrain.net
Agent
340 Gilmour Street
Suite 100
Ottawa, Ontario
K2P 0R3
Telephone: (613) 695-8855 Ext: 102
FAX: (613) 695-8580
Email: mfmajor@supremeadvocacy.ca
Party: Attorney General of Canada
Counsel
Claude Joyal
200 René-Lévesque Blvd West, East Tower, 9th floor
Guy-Favreau Complex
Montréal, Quebec
H2Z 1X4
Telephone: (514) 515-8132
FAX: (514) 496-7876
Email: caroline.laverdiere@justice.gc.ca
Agent
Department of Justice Canada, Civil Litigation Sector
50 O’Connor Street, Suite 500
Ottawa, Ontario
K1A 0H8
Telephone: (613) 295-0765
FAX: (613) 954-1920
Email: SCCAgentCorrespondentCSC@justice.gc.ca
Party: Directeur général des élections du Canada, Directeur du scrutin de la circonscription de Terrebonne
Counsel
Jean-Philippe Dionne
1250, boulevard René-Lévesque Ouest, 20e étage
Montréal, Quebec
H3B 4W8
Telephone: (514) 842-7821
FAX: (514) 845-6573
Email: daniel.baum@langlois.ca
Agent
225, montée Paiment
2e étage
Gatineau, Quebec
J8P 6M7
Telephone: (819) 771-7393
FAX: (819) 771-5397
Email: p.landry@noelassocies.com
Party: Auguste, Tatiana
Counsel
Frédéric Arcand
824, avenue Myrand
Québec, Quebec
G1V 2V5
Telephone: (581) 814-0774
FAX: (581) 814-0774
Email: mvien@svavocats.com
Agent
50, rue O'Connor, bureau 1313
Ottawa, Ontario
K1P 6L2
Telephone: (613) 702-5560
FAX: (613) 702-5561
Email: mpower@juristespower.ca
Party: Charles, Adrienne
Counsel
Marie-Eve Labonté
800, rue du Square-Victoria
Bureau 3500
Montréal, Quebec
H3C 0B4
Telephone: (514) 394-4515
FAX: (514) 397-7600
Email: csemerjian@fasken.com
Agent
55 rue Metcalfe
Bureau 1300
Ottawa, Ontario
K1P 6L5
Telephone: (613) 696-6904
FAX: (613) 230-6423
Email: sarseneault@fasken.com
Party: Beaudoin, Maxime
Counsel
438, rue McGill, bureau 500
Montréal, Quebec
H2Y 2G1
Telephone: (514) 316-1355 Ext: 718
Email: jdussault@delegatus.ca
Party: Cantore, Maria
This party is not represented by counsel.
Party: Rankin, Benjamin
This party is not represented by counsel.
Summary
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 election in electoral district must be cancelled — Canada Elections Act, S.C. 2000, c. 9, ss. 524(1)b), 531(2).<br><br>
Summary
Case summaries are prepared by the Office of the Registrar of the Supreme Court of Canada (Law Branch). Please note that summaries are not provided to the Judges of the Court. They are placed on the Court file and website for information purposes only.
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.
Lower court rulings
Contested election application dismissed.
Memorandums of argument on application for leave to appeal
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Related links
Factums on appeal
The factums of the appellant, the respondent and the intervener will be posted here at least 2 weeks before the hearing unless they contain personal information, information that is subject to a publication ban, or any other information that is not part of the public record. You may also obtain copies of factums by filling out the Request for Court records form or by contacting the Court’s Records Centre either by email at records-dossiers@scc-csc.ca or by telephone at 613‑996‑7933 or at 1‑888‑551‑1185.
If you have questions about a factum or want permission to use a factum, please contact the author of the factum directly. Their contact information appears on the first page of each factum.
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