Michael Ma, MP for Markham–Unionville, has defected from the Conservative Party to join Prime Minister Mark Carney’s Liberals, bringing the governing party within one seat of a parliamentary majority. Ma cited a desire to "focus on solutions, not division" and praised Carney’s steady approach. The move is a setback for Conservative leader Pierre Poilievre, who faces a leadership review in January and has seen several colleagues depart. Analysts say one more defection could hand the Liberals a majority and reshape the federal political timeline.
Conservative MP Michael Ma Joins Prime Minister Mark Carney’s Liberals — Liberals Now One Seat From Majority
Canadian Prime Minister Mark Carney arrives on Parliament Hill in Ottawa, Canada, Thursday, Dec. 11, 2025. (Spencer Colby/The Canadian Press via AP)(ASSOCIATED PRESS)
Michael Ma, the Member of Parliament for Markham–Unionville, has left the Conservative Party to join Prime Minister Mark Carney’s Liberal caucus, a move that now places the governing Liberals just one seat short of a parliamentary majority.
The Switch And What It Means
Ma is the second Conservative MP in just over a month to cross the floor. In a statement, he said he entered politics "to focus on solutions, not division," and added that he had "concluded that Prime Minister Mark Carney is offering the steady, practical approach we need to deliver on the priorities I hear every day while door-knocking in Markham–Unionville."
The change brings the Liberals within a single seat of a majority government — a threshold that would allow them to pass legislation without needing formal support from an opposition party. Political analysts say one more defection could hand the Liberals that majority and materially alter the federal political calendar.
Public Welcome And Reaction
Carney publicly welcomed Ma at the Liberal Party Christmas event. Ma later quipped, "Wow, such a big welcome." Carney joked about the growing coalition of supporters, saying, in good humor, that "we are all about Santa, not about the Grinch."
Conservative Leader Pierre Poilievre stands in the House of Commons during Question Period on Parliament Hill in Ottawa, Canada, Thursday, Dec. 11, 2025. (Spencer Colby/The Canadian Press via AP)(ASSOCIATED PRESS)
Conservative leader Pierre Poilievre criticized Ma’s decision on social media, saying "Michael Ma was elected as a Conservative by the constituents of Markham–Unionville to fight against Liberal inflationary spending driving up the cost of living in his community. Today, he chose to endorse the very policies he was elected to oppose." Poilievre is scheduled to face a leadership review vote in January; he lost the last national election in April and briefly lost his own seat before returning to the House of Commons.
Context And Analysis
Poilievre has lost three Conservative MPs in recent weeks, and another Conservative lawmaker resigned after discussions with Carney about a possible floor crossing. Daniel Béland, a political science professor at McGill University, described two floor crossings in such a short period as "rare" and said the Conservative establishment is likely unsettled by the trend. Béland warned that a further defection could deliver a Liberal majority, potentially delaying federal elections and giving Poilievre’s internal critics more time to regroup.
Since replacing Justin Trudeau as prime minister and winning national contests, Carney has steered the Liberal Party toward the centre, according to observers. Some reports also recall earlier tensions with former U.S. President Donald Trump — cited in political commentary as a historical backdrop — though those remarks are tangential to the floor-crossing itself.
As the parliamentary arithmetic shifts, both parties appear to be preparing for intensified internal and public political battles in the months ahead.
