Conservative MP Marilyn Gladu’s defection to the Liberals has all but secured a majority for Prime Minister Mark Carney, reshaping the ballot box question for Monday’s by-election in the hotly contested Montreal-area riding.
Whether the Carney government lands a real “working” majority mandate of 173 seats in the House of Commons is no longer up to voters in Terrebonne, after former Conservative MP Marilyn Gladu crossed the floor Wednesday.
The defection, plus likely Liberal wins in upcoming Ontario byelections, mean the Carney government is expected to command a majority government by next week, no matter the outcome in Terrebonne.
This has energized the Bloc Québécois, whose byelection strategy in the riding centered on local priorities rather than countering a prospective Liberal majority.
Leader Yves-François Blanchet told iPolitics many believe the latest floor crossing to the Liberals is great news for the sovereigntists.
“This strips the Liberals of their only argument in Terrebonne, where they’ve had nothing to say other than asking for a majority for Mark Carney,” said Blanchet.
At a press conference Wednesday, Blanchet poked fun at the Liberal quest for a majority government.
“… Now we have to vote for them so they can have a mega majority? At some point there will be no Conservative MPs left.”


Ahead of Monday’s by-elections, several Bloc Québécois MPs travelled to Terrebonne to support their former colleague and candidate Nathalie Sinclair-Desgagné, who lost to the Liberals by a single vote in the 2025 federal election.
“Last year was a special circumstance,” said Sinclair-Desgagné, pointing to tariffs and aggressive rhetoric coming out of the U.S. “We’re now back in a much more familiar territory.”
Acknowledging some voters might have been swayed by Carney’s response to global instability last year, Blanchet called on those with “the Bloc in their hearts” to “return home” this time around.


iPolitics tagged along with Bloc Québécois MPs Mario Simard and Alexis Deschênes as they knocked on doors of a residential Terrebonne neighbourhood.
Many voters seemed undecided.
Some expressed concern about Alto’s high speed rail project between Toronto and Quebec City, with one woman telling the Bloc MPs she feared the expropriation process would reduce the value of her home.
Others seemed sympathetic to the Bloc and its ideals, but praised Carney’s performance internationally.
“He’s won the respect of the entire world, and he hasn’t been putting up with Trump,” said one voter.
A recurring theme was concern about disruptive U.S. actions on the global stage, including attacks on Iran and the Canadian economy.
One voter, a “very proud Québécois” and lifelong Bloc supporter, admitted he felt the province had “missed the boat” on independence—an option he finds even less tenable now given the current geopolitical climate.








