Prime Minister Mark Carney’s Liberal government has moved to within one seat of securing a parliamentary majority after longtime Conservative MP Marilyn Gladu announced she is crossing the floor to join the governing caucus. The decision strengthens the Liberals’ position in the House of Commons and adds momentum ahead of several upcoming by-elections.
In a public statement explaining her move, Gladu said the country is facing an unusually challenging period and that constituents in her riding are looking for practical leadership and a clear strategy to strengthen Canada’s economic independence. She said those concerns influenced her decision to support the government’s direction and formally join the Liberal caucus.
Gladu has represented the southwestern Ontario riding of Sarnia—Lambton—Bkejwanong since 2015 and has served in several senior opposition critic roles during her time with the Conservative Party. The riding plays a key role in Canada’s energy and petrochemical sector, making her shift politically notable given the region’s industrial importance. She also previously entered the 2020 Conservative leadership race but was ruled ineligible by party officials during the process.
Prime Minister Carney welcomed Gladu’s decision, highlighting her background as an engineer and business leader and expressing confidence she would contribute meaningful experience to the government’s work. Her move marks the fifth time in recent months that a Member of Parliament has joined the Liberals from another party, including four former Conservatives.
The development drew reaction from Yves-François Blanchet, who argued the ideological distance between the Liberals and Conservatives appears to be narrowing. He suggested the shift raises questions among progressive voters about representation within the Liberal caucus and emphasized his party’s continued focus on climate policy as a distinguishing priority.
With Gladu now seated among Liberal MPs, the government holds 171 seats, just one short of the 172 required for a majority. The Liberals are expected to defend key Toronto area ridings in upcoming by-elections, including University—Rosedale and Scarborough Southwest, and are also targeting the Quebec riding of Terrebonne after the Supreme Court of Canada ordered a new vote following last year’s one-vote election result controversy.
