Carney Liberals Expected to Win Parliamentary Majority in Monday By-Elections

The arithmetic in Canada's House of Commons shifted dramatically when Conservative MP Marilyn Gladu crossed the floor to join Mark Carney's Liberal caucus on April 8, lifting the government to 171 seats in the 338-seat House, one short of the 172 needed for a slim majority. Two Toronto by-elections on Monday, April 13, are widely expected to erase that gap entirely.

University-Rosedale and Scarborough Southwest, both considered safe Liberal ridings, are open after former Finance Minister Chrystia Freeland resigned her seat and Bill Blair was appointed Canada's High Commissioner. A third by-election in Terrebonne, Quebec, is far less certain. The Supreme Court of Canada annulled that riding's 2025 result on February 13 after finding a clerical error on mail ballot return addresses; Liberal candidate Tatiana Auguste had beaten Bloc Québécois incumbent Nathalie Sinclair-Desgagné by exactly one vote, and both are now headed for a rematch. Western University political science chair Laura Stephenson called a potential outcome "a very, very slim, itty-bitty majority" if the Liberals take Terrebonne. Conservative MP Michelle Rempel Garner was blunter on her podcast, saying Carney's party is "expected to win hands down" in both Toronto ridings.

Because House Speaker Francis Scarpaleggia is himself a Liberal MP, the government ideally wants 173 seats to more comfortably control House business, a threshold the two Toronto wins alone would reach.

The stakes of that arithmetic are substantial. A majority allows Carney to pass budgets and win confidence votes without negotiating with the NDP, Bloc Québécois, or any other party. For U.S. observers in particular, a majority government in Ottawa accelerates action on the files most likely to affect bilateral relations: trade response to Donald Trump's tariffs, Arctic sovereignty and defense posture, and energy infrastructure. Those files have moved slowly under minority arithmetic since the Liberals won 169 seats in the April 2025 federal election.

Gladu herself embodies the tariff pressure driving Liberal consolidation. She won Sarnia-Lambton-Bkejwanong, a riding that sits directly on the U.S.-Canada border, with over 53% of the vote in 2025, the largest mandate of any of the five floor-crossers. Despite having endorsed Poilievre in the 2022 Conservative leadership race and having previously graded Carney's budget a D, she stood alongside the Prime Minister in Ottawa and said: "We need a serious leader who can address the uncertainty that has arrived due to the unjustified American tariffs."

Gladu is the fifth MP to cross the floor to the Liberals since the 2025 election and the fourth from the Conservative caucus, following Nova Scotia's Chris d'Entremont, Markham-Unionville's Michael Ma on December 11, 2025, Edmonton's Matt Jeneroux on February 18, 2026, who cited Carney's World Economic Forum speech in Davos as a catalyst, and former NDP MP Lori Idlout of Nunavut in March 2026. Reports put up to 10 additional MPs in active talks to switch sides.

The announcement landed with compounded political force. On the same day, Poilievre's director of communications, Katy Merrifield, announced her resignation, and the defection came just one day before the Liberal Party's annual convention in Montreal. Political analyst Scott Reid called Gladu's move "an absolute mule kick" to Poilievre on CTV News. Poilievre fired back on social media, noting that Gladu had publicly argued in January 2026 that floor-crossers should face voters in a by-election.

Carney kept his tone measured: "What's important is that we command the confidence of the House. Sometimes that will come officially as members of the governing team and sometimes that will come through the vote."

By Tuesday morning, the institutional question of whether Canada has a majority government will likely be settled. The policy consequences, on trade, defense, and economic resilience, would follow almost immediately.