2026 Terrebonne federal by-election

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Riding of Terrebonne
Registered	91,344
Turnout	51.25% ( 16.69 pp)
First party Second party   LPC BQ Candidate Tatiana Auguste Nathalie Sinclair-Desgagné Party Liberal Bloc Québécois Last election 38.741%[a] 38.739%[b] Popular vote 22,445 21,777 Percentage 48.32% 46.89% Swing  9.59 pp  8.15 pp
MP before election Vacant[c] Elected MP Tatiana Auguste Liberal

A by-election was held on April 13, 2026, to elect a member of Parliament (MP) to represent Terrebonne, Quebec, in the House of Commons for the remainder of the 45th Parliament after the riding's result in the 2025 general election was annulled by the Supreme Court of Canada on February 13, 2026, vacating the seat held by the then-Liberal Party MP Tatiana Auguste.^[1] Auguste held the seat by a margin of less than a thousand votes.

The identity of the victor of the 2025 federal election in Terrebonne remained uncertain for close to a year following the election. Election night preliminary results had Liberal challenger Tatiana Auguste leading incumbent Bloc Québécois MP Nathalie Sinclair-Desgagné by thirty five votes. The lead was however short-lived as the tally verification process put Sinclair-Desgagné back in the lead by forty-four votes instead, a margin small enough to trigger an automatic judicial recount. The process also reported over 900 rejected ballots. The recount, overseen by Quebec Superior Court Justice Danielle Turcotte and conducted in early May, 2025 increased the total number of valid ballot by seventy-four. The lion's share of the gains went to Auguste, putting her back on top by a single vote margin, and she was declared elected accordingly. Auguste was subsequently sworn in and seated as MP for Terrebone.

A printing error on the special ballot return envelopes was reported after the recount was completed. Defeated MP Nathalie Sinclair-Desgagné contested Auguste's election at the Quebec Superior Court citing this printing error by Elections Canada as an irregularity, but her application was rejected in October 2025.^[2] She proceeded to appeal the ruling to the Supreme Court of Canada. Following a hearing by the full bench of Canada's top court on February 13, 2026, the election results was annulled and Auguste was unseated, leading to this by-election.^[1][3]

The top court's decision was the first time the election of a MP was successfully overturned through the contested elections provisions in the Canada Elections Act. The last time a seat was vacated by a court ruling was in 1989 when the Supreme Court of Ontario vacated the seat for York North under the previous Dominion Controverted Elections Act.^[4][5] The last time the nation's top court overruled a lower court's determination of a federal election outcome or voided a federal election outcome was over eight decades ago in 1942, when it unseated Liberal MP for Stanstead Robert Davidson for bribing voters with whisky and cash.^[6]

A writ for the by-election could be issued no sooner than February 27 and no later than August 1, 2026.^[7] Under the Canada Elections Act, the minimum length of a campaign is 36 days between dropping the writ and election day, but must not exceed 50 days. The by-election must also be held on a Monday within that time frame.^[8] Accordingly, the earliest possible date for the by-election was April 6 and the latest was September 28.^[7]

On March 8, the writ was issued for a by-election to be held on April 13.^[9][10][11] Nominations closed on March 23.^[12]

After reviewing its internal procedures, Elections Canada announced that, to avert the possibility of misdirected ballots in the future, special ballots will no longer be manually prepared by a riding office, but will be centrally and automatically prepared at its Ottawa office. However, the change was not expected to be fully implemented until the fall.^[13]

The candidates in 2025 have reappeared for the by-election:

• Auguste and Sinclair-Desgagné had already been confirmed as candidates before the by-election was called.^[14]

• Conservative Adrienne Charles's candidacy was announced on March 11.^[15] The Greens are fielding Benjamin Rankin again,^[16] as are the NDP with Maxime Beaudoin.^[17] Maria Cantore is also returning for the PPC.^[18]

The Longest Ballot Committee chose Terrebonne as their target out of three by-elections being held simultaneously.^[19] This resulted in a total of 48 candidates when nominations closed, and Elections Canada announced that write-in ballots similar to those used in Battle River—Crowfoot in 2025 would be employed.^[20]

Sinclair-Desgagné used the slogan Une voix qui compte! ("A voice/vote that counts!"). She promoted the Bloc platform for supporting seniors and first-time home buyers, and voiced concerns over the proposed routing of the Alto high-speed rail line and potential expropriations for it in the riding.^[21] Local observers noted that, besides the issue of the Alto line, other concerns included the construction of new housing and the decontamination of a former DND firing range to make way for a new interchange on Autoroute 640.^[22] Both the Bloc and Liberals agreed that the campaign is local.^[23] The Liberals concentrated their efforts on the ground, minimizing participation in local debates,^[24] but they still expected the result to be close.^[25]

Bloc leader Yves-François Blanchet laughed off suggestions that "fake candidates" could be nominated in the concurrent by-elections being held in Scarborough Southwest and University—Rosedale, in order to create extra campaign financing room in the Terrebonne contest.^[26]

At a Liberal rally, Auguste's advocate claimed that she had "won fair and square" in 2025, and that the Supreme Court of Canada (SCC) had later decided that it wanted to punish Elections Canada. At a subsequent Bloc rally, Sinclair-Desgagné described that as saugrenu ("absurd"), and said that people would find it strange that the Liberals would distance themselves from a decision of the SCC where normally it would be embraced by the party. That rally also featured posters bearing the slogan Reprenons notre place le 13 avril ("Let's take back our place/seat on April 13").^[27]

It was reported that the advance polls conducted a week before Election Day attracted a turnout of almost 20%, lower than the 25% seen in 2025, but almost double those happening in the Toronto-area by-elections.^[28]

v t e Canadian federal by-election, April 13, 2026: Terrebonne 2025 result annulled by Supreme Court
Party	Candidate	Votes	%	±%
	Liberal	Tatiana Auguste	22,445	48.32	+9.59
	Bloc Québécois	Nathalie Sinclair-Desgagné	21,777	46.89	+8.15
	Conservative	Adrienne Charles	1,548	3.33	-14.85
	New Democratic	Maxime Beaudoin	248	0.53	-2.05
	Green	Benjamin Rankin	194	0.42	-0.63
	People's	Maria Cantore	113	0.24	-0.47
	Rhinoceros	Mark Moutter	61	0.13	–
	Independent	Julie St-Amand	7	0.02	–
	Independent	Nicolas Champagne	5	0.01	–
	Independent	Geneviève Dorval	4	0.01	–
	Independent	Myriam Beaulieu	3	0.01	–
	No Affiliation	Sébastien CoRhino	3	0.01	–
	Independent	Samuel Pignedoli	3	0.00	–
	Independent	Myles René Laurent St. Pierre	3	0.01	–
	Independent	Alex Banks	2	0.00	–
	Independent	Sophia Bearden	2	0.00	–
	Independent	Samuel Ducharme	2	0.00	–
	Independent	Elizabeth Dupuis	2	0.00	–
	Independent	Laurie Goble	2	0.00	–
	Independent	Seyed Hosseini Lavasani	2	0.00	–
	Independent	Ryan Huard	2	0.00	–
	Independent	Krzysztof Krzywinski	2	0.00	–
	Independent	Bryan Wang	2	0.00	–
	Independent	Danica Boe	1	0.00	–
	Independent	Jenny Cartwright	1	0.00	–
	Independent	Jaël Champagne Gareau	1	0.00	–
	Independent	Jayson Cowan	1	0.00	–
	Independent	Michael Dyck	1	0.00	–
	Independent	Anthony Hamel	1	0.00	–
	Independent	Chris Kowalchuk	1	0.00	–
	Independent	John Francis O'Flynn	1	0.00	–
	Independent	Spencer Rocchi	1	0.00	–
	Independent	Pascal St-Amand	1	0.00	–
	Independent	Vivian Unger	1	0.00	–
	Independent	Jeani Boudreault	0	0.00	–
	Independent	Gerrit Dogger	0	0.00	–
	Independent	Ysack Dupont	0	0.00	–
	Independent	Alexandra Engering	0	0.00	–
	Independent	Emily Goose	0	0.00	–
	Independent	Kazimir Haykowsky	0	0.00	–
	Independent	Jack Jean-Louis	0	0.00	–
	Independent	Joseph Alain Matthew Laveault	0	0.00	–
	Independent	Jocelyn LeBlanc-Courchaine	0	0.00	–
	Independent	Lanna Palsson	0	0.00	–
	Independent	Lajos Polya	0	0.00	–
	Independent	Kayll Schaefer	0	0.00	–
	Independent	Justin Steinburg	0	0.00	–
	Independent	Alon Weinberg	0	0.00	–
Total valid votes/expense limit			46,443
Total rejected ballots			371
Turnout			46,814	51.25	-16.68
Eligible voters			91,344
	Liberal hold		Swing		+0.72
Source: Elections Canada

2025 nullified result

v t e 2025 Canadian federal election: Terrebonne
Party	Candidate	Votes	%	±%
	Liberal	Tatiana Auguste	23,352	38.741	+9.37
	Bloc Québécois	Nathalie Sinclair-Desgagné	23,351	38.739	−2.66
	Conservative	Adrienne Charles	10,961	18.18	+7.73
	New Democratic	Maxime Beaudoin	1,556	2.58	−4.07
	Green	Benjamin Rankin	630	1.05	−0.38
	People's	Maria Cantore	428	0.71	−1.97
Total valid votes			60,278	98.63
Total rejected ballots			840	1.37	-0.88
Turnout			61,118	67.93	+1.74
Eligible voters			89,966
	Liberal notional gain from Bloc Québécois		Swing		+6.02
Source: Elections Canada[29][30]
Notes: Results were annulled by the Supreme Court of Canada on February 13, 2026.[31] The results were also subject to an automatic judicial recount on May 7, 2025.[32] The number of eligible voters does not include election day registrations.

2021 valid result (redistributed)

2021 federal election redistributed results[33]
Party		Vote	%
	Bloc Québécois	23,298	41.40
	Liberal	16,528	29.37
	Conservative	5,886	10.46
	New Democratic	3,742	6.65
	People's	1,506	2.68
	Green	802	1.43
	Others	4,518	8.03

2021 valid result (actual)

v t e 2021 Canadian federal election: Terrebonne
Party	Candidate	Votes	%	±%	Expenditures
	Bloc Québécois	Nathalie Sinclair-Desgagné	24,270	41.17	-9.42	$28,625.35
	Liberal	Eric Forget	17,475	29.64	+0.39	$6,336.80
	Conservative	Frédérick Desjardins	6,183	10.49	+2.92	$8,029.08
	New Democratic	Luke Mayba	3,913	6.64	-0.91	$7,745.37
	Independent	Michel Boudrias	3,864	6.55	N/A	$16,574.97
	People's	Louis Stinziani	1,594	2.70	+2.05	$0.00
	Green	Dave Hamelin-Schuilenburg	847	1.44	-2.28	$103.94
	Free	Nathan Fortin-Dubé	803	1.36	N/A	$25.71
Total valid votes/expense limit			58,949	97.75	–	$119,339.41
Total rejected ballots			1,355	2.25	+0.20
Turnout			60,304	66.25	-4.06
Eligible voters			91,028
	Bloc Québécois hold		Swing		-4.90
Source: Elections Canada[34]
Notes: The incumbent MP, Michel Boudrias, was not renominated as the candidate for the Bloc Quebecois, and subsequently ran as an Independent[35]

• 2025 Terrebonne provincial by-election
• Terrebonne in the 2025 Canadian federal election