The political landscape in Ottawa is shifting as the federal byelection in Terrebonne approaches, with the Liberal Party poised to potentially secure a more stable majority government. Initially seen as a straightforward path to majority status, this Montreal-area riding has now become a critical battleground that could determine the government's ability to implement its agenda effectively.
The Path to a Secure Majority
Recent developments have altered the calculus for Prime Minister Mark Carney's government. While the Liberals were already almost guaranteed a majority, the crossing of NDP MP Lori Idlout to their ranks has reduced some immediate pressure. However, political analysts emphasize that reaching 172 seats—a true majority in the House of Commons—remains essential for governing stability.
Sandra Aubé, vice-president of federal affairs at Quebec-based firm TACT Conseil, explains the significance: "To have such a narrow majority with just one extra seat, or to remain at the current count, means the Liberals won't have any margin of error for absences or defections."
The Current Seat Count and Upcoming Battles
The Liberals currently hold 170 seats, bolstered by recent floor-crossings from Conservative MP Matt Jeneroux and Idlout. The government expects to gain two additional seats next month through byelections in Toronto's University—Rosedale and Scarborough Southwest, which would bring them to the crucial 172 threshold.
However, Terrebonne presents a unique challenge. The riding became contested after the Bloc Québécois successfully appealed to the Supreme Court to annul last spring's one-ballot Liberal victory, citing a procedural error involving a mistakenly returned Bloc ballot. This has transformed what might have been a routine election into a fiercely competitive race.
The Terrebonne Showdown
Liberal forces have mobilized extensively in the Montreal suburb, supporting candidate Tatiana Auguste, who previously served as MP until the Supreme Court decision last month. Auguste benefits from Carney's rising popularity in Quebec and aims to secure the seat permanently.
Meanwhile, the Bloc Québécois is rallying behind candidate Nathalie Sinclair-Desgagné, who held the seat from 2021 to 2025 and is determined to reclaim it. Bloc Leader Yves-François Blanchet suggests that the prospect of Liberals reaching 172 seats might actually help his party, as voters "will have the possibility to vote according to their own specific values, convictions, and interests."
The 172-Seat Debate: Magic Number or Poison Pill?
Éric-Antoine Ménard, vice-president and head of Quebec operations at NorthStar Public Affairs, challenges conventional wisdom in a recent Substack post. He argues that 172 seats isn't a "magic number" and that Liberals would need 173 or more to truly control the House.
"The idea behind getting to 173 is that you no longer need the Speaker to cast a vote to win on a deadlock," Ménard explains. "That's really the key thing, because there are rules that apply to how the Speaker uses his tiebreaking vote, and they're very ancient rules."
He notes that Liberal MP Francis Scarpaleggia, as Speaker, isn't bound to party discipline. When breaking ties, Scarpaleggia must preserve the status quo and allow debate to continue whenever possible under parliamentary tradition.
The Double-Edged Sword of a Working Majority
Ménard further observes that while a "working majority" benefits the government, it can also become a "poison pill" in practice. "It definitely changes the caucus management dynamics, because all of a sudden, every backbench MP is the tiebreaking vote," he warns.
This creates a delicate balancing act for the Liberal leadership. Each member's vote becomes critically important, potentially empowering backbenchers and complicating party discipline. The Terrebonne outcome could thus determine not just whether the Liberals achieve a majority, but what kind of majority they govern with—one that provides stability or one that introduces new vulnerabilities.
As the byelection campaign intensifies, all eyes remain on this Quebec riding that has unexpectedly become central to Canada's political future.
