Guilbeault vows to continue climate change fight as he announces resignation

The former Liberal cabinet minister’s decision puts Prime Minister Mark Carney on the defensive

Former Liberal cabinet minister Steven Guilbeault announced his resignation from politics Wednesday, saying he wants to keep up his fight against climate change in other ways.

His decision put Prime Minister Mark Carney on the defensive once again about the Liberals’ climate change policy.

Mr. Guilbeault, a career environmentalist, played a key role in many of the previous Liberal government’s climate initiatives now being watered down, stalled or reversed by the current government. He plans to resign from his seat later this summer.

The MP was first elected to the Montreal riding of Laurier-Sainte-Marie in 2019. He was a star recruit for the Liberals at the time, and swiftly entered cabinet, first at Heritage before becoming the environment and climate change minister in 2021. Mr. Carney put him back to Heritage after he became prime minister.

He quit Mr. Carney’s cabinet in November, 2025, over the new Ottawa-Alberta energy accord, issuing a scathing letter laying out his reasons for concluding the deal undercuts environmental protections.

But, as he spoke about his career in politics from the floor of the House of Commons late Wednesday, Mr. Guilbeault did not outright criticize Mr. Carney’s record on the file.

Instead, he reflected on his decades of environmental activism before being honoured by colleagues from other parties.

“The fight is not over,” he said. “I will continue my battle for a greener, safer planet.”

The Alberta-Ottawa deal originally announced in November lays the groundwork for a new bitumen pipeline to the West Coast. It also removes the oil and gas emissions cap and suspends clean electricity regulations – two policies Mr. Guilbeault championed when he was environment minister under former prime minister Justin Trudeau.

Mr. Guilbeault’s decision now to leave politics altogether follows Ottawa and Alberta agreeing on the finer points of the deal earlier this month. The government has also recently proposed major changes to environmental assessments.

Mr. Carney said Wednesday he has known for some time that Mr. Guilbeault could leave, and said the decision was ultimately up to him.

When asked by a reporter whether the Liberal Party has abandoned the environment, Mr. Carney paused on his way up the stairs from his party’s caucus meeting on Parliament Hill and came back down to answer, in French, no, not at all.

He said much progress has been made, citing the government’s recently announced nature strategy and commitments to clean power.

In an earlier statement released by his office, Mr. Carney spoke glowingly of the Quebec MP’s contributions. He said Mr. Guilbeault’s work has “always been guided by his convictions and driven by his pursuit of a stronger, more inclusive and more sustainable future.”

The government remains committed to climate action, the Prime Minister said. “We are advancing these missions with the same determination, a new spirit of partnership, and a renewed focus on results.”

A growing chorus of environmental groups and activists, however, have criticized his approach.

They say Mr. Carney has betrayed the climate movement and argue that his policies in government run counter to the stand he took on the issue in private life.

The Bloc Québécois, NDP and Green Party all said Mr. Guilbeault’s decision to go is concerning.

“It’s a huge wake-up call, hopefully for everybody,” NDP MP Gord Johns said.

“It takes incredible courage what our colleague is doing today to stand up for climate science, for environmental protection, and future generations when powerful interests inside government are pushing in the opposite direction.”

Other Liberals commended Mr. Guilbeault’s work and wished him well, and said others will now pick up the fight for the environment internally.

“There are many of us who will continue that work within the party and within the government, and that’s our role,” said MP Will Greaves, who has also previously criticized the Alberta-Ottawa MOU.

While Mr. Guilbeault was environment minister, his counterpart in the energy department was B.C. MP Jonathan Wilkinson.

Mr. Wilkinson told The Globe that he believes other MPs on the Liberal side will keep advocating for climate action.

Asked about Mr. Carney’s unwinding of the marquee policies that he and Mr. Guilbeault brought in under Mr. Trudeau, the MP said the world has changed.

Climate has taken a “step back everywhere,” Mr. Wilkinson said, pointing to the experience in Canada, Europe, Japan and South Korea.

“But I do think, and I do believe that the Prime Minister is committed to addressing the climate issue,” Mr. Wilkinson said. “I think you will see the government take important steps forward.”

Mr. Wilkinson is resigning his B.C. seat at the end of the sitting and moving to Brussels, where he will be Canada’s ambassador to the European Union.

Mr. Carney’s Liberals currently have a two-seat majority, and the departures of both Mr. Guilbeault and Mr. Wilkinson are not the only ones.

Toronto Liberal MP Nate Erskine-Smith is also expected to resign, as is former NDP Quebec MP Alexandre Boulerice, who is currently sitting as an independent.

That will mean four by-elections to be called over the coming months.

Though public-opinion polling shows Mr. Carney’s team with the upper hand, the by-elections are expected to be hotly contested races.

The Liberals will aim to hang on to their majority, while opposition parties try to knock them back to a minority government.