Steven Guilbeault resigns as MP, warns Canada is ‘backsliding’ on climate
OTTAWA — Steven Guilbeault quit cabinet last year over a pipeline. Now he’s quitting Parliament. His message: the country is backsliding on climate, and the Liberal government that recruited him as an environmental star no longer wants to hear it. The announcement Wednesday that Guilbeault will leave his Montreal riding of Laurier—Sainte-Marie this summer triggers a by-election the Liberals should win, but the political fallout stretches far beyond one seat.
It’s the loudest signal yet that Prime Minister Mark Carney’s government has abandoned the climate priorities that defined the Trudeau years, and that the most prominent environmental voice in federal politics can’t stomach staying inside a tent pitched on bitumen.
A rift over energy and climate
The tensions have been building for months. When Guilbeault resigned from Carney’s cabinet last year, the flashpoint was an energy memorandum of understanding with Alberta that explicitly includes advancing a bitumen pipeline. That deal, Guilbeault told the House, crossed his red line. Leaving cabinet was a warning. Leaving Parliament is an indictment.
Carney’s office, asked about the resignation, gave a response so brief it practically underlined Guilbeault’s point. The prime minister’s own remarks to reporters (he thanked Guilbeault, said they’d worked well together, and ignored the climate critique entirely) only deepened the sense of a deliberate sidestepping.
The energy deal that split the cabinet
The Ottawa-Alberta accord was hammered out during the trade war with Washington, with Carney arguing that diversifying export markets away from an unpredictable American administration demands new pipeline infrastructure. For Guilbeault — a co-founder of the Quebec environmental group Équiterre and a former Greenpeace campaigner — any new bitumen pipeline is a line that can’t be erased.
He served as environment minister for nearly four years under Justin Trudeau. Under his watch, the consumer carbon price became law. He pushed through the clean fuel standard. He also championed a first-ever pledge to cap emissions from oil and gas. That’s a record of institutional climate action — and now he’s walking away from the institution.
Reaction from across the aisle
Trudeau, who recruited Guilbeault as a star candidate in 2019, called him a figure of “conviction, integrity and heart” dedicated to protecting the environment. Conservative Leader Pierre Poilievre was quick to frame the resignation as vindication for critics who always viewed Guilbeault as a job-killing radical. And Green Party Leader Elizabeth May went after Carney directly, wondering aloud whether the prime minister had become indistinguishable from a Conservative. “I wonder who Mark Carney is,” May said. “When did the Liberal platform become the Conservative platform?”
Other Liberals were more careful. Quebec MP Jean-Yves Duclos spoke of Guilbeault as a friend, while Transport Minister Steven MacKinnon acknowledged the tension, insisting the Liberals still have an “urgent” climate agenda alongside the trade war and security threats.
Premiers clash over separatism talk
Manitoba Premier Wab Kinew and Alberta Premier Danielle Smith are now trading shots over Smith’s suggestion that Alberta could hold a referendum on separation. Kinew calls it reckless. Smith says Albertans deserve a say. The spat is part of a broader mood of fractious federalism, with provinces at odds over resources and carbon pricing. Carney must somehow hold this map together, and Guilbeault’s exit makes the centrists and the climate wing more suspicious of each other.
From activist to minister and back
Guilbeault entered federal politics in 2019 as a Liberal banner-waver for climate action. He leaves now convinced the party has lost its nerve. He’ll keep advocating from outside, possibly with an international environmental group. The by-election in his safe Liberal riding will be a quiet polling test, but the real impact is the message it sends to urban voters who backed Trudeau’s climate promises.
The first ministers’ meeting looms
Next week, Carney hosts a first ministers’ meeting in Ottawa. The Alberta energy deal, carbon pricing, and the U.S. trade war are all on the table. Smith and Kinew will be in the same room. And the absence of Guilbeault’s voice inside the government will be impossible to ignore. He said he’ll keep fighting from outside. The question is whether anyone on the inside is still listening.