Updated November 27, 2025 @ 5:40pm
Culture Minister Steven Guilbeault has resigned from Prime Minister Mark Carney’s cabinet to protest Ottawa signing an agreement with Alberta on a proposed new pipeline.
In a social media post Thursday, Guilbeault said he submitted his resignation to Carney Thursday afternoon "with great sadness."
"Despite this difficult economic context, I remain one of those for whom environmental issues must remain front and centre," he wrote. "That is why I strongly oppose the memorandum of understanding between the federal government and government of Alberta."
The environmentalist and longtime climate activist — who said he intends to stay on as a Liberal MP — has been a key fixture in the Liberal government for the past six years, and was also serving as Carney's Quebec lieutenant.
Guilbeault avoided TV cameras and questions from reporters for several days as news emerged of progress on an agreement between the federal government and Alberta on the energy file.
On Thursday, he made it clear that he was quitting cabinet over the pipeline deal and the government's pullback from major federal climate policies.
"Finally, over the past few months, several elements of the climate action plan I worked on as minister of the environment have been, or are about to be, dismantled," Guilbeault wrote.
He went on to cite the consumer carbon price, the electric vehicle sales mandate, the oil and gas emissions cap and the framework to eliminate fossil fuel subsidies.
"In my view, these measures remain essential to our climate action plan," Guilbeault wrote.
He added that the decision to exempt Alberta from the clean energy regulations "in exchange for stricter industrial carbon pricing rules" and the Pathways Alliance carbon capture project "is, in my view, a serious mistake."
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Liberal MPs downplayed for reporters earlier this week reports of deep discontent within caucus over Ottawa's agreement with Alberta.
In a social media post Thursday, Conservative MP Dan Albas praised Guilbeault for taking a stand.
"Yesterday, I accused Steven Guilbeault of not having the courage of his convictions by not resigning from cabinet. I was wrong. He does," Albas wrote.
"While I don’t agree with him on policy, I will say resigning over principle is an honourable act."
Liberal MP Ali Ehsassi called Guilbeault an energetic and passionate colleague after learning the news late Thursday afternoon.
He said the resignation is "very regrettable."
"I know that this prime minister takes the environment very seriously, as does the responsible minister," Ehsassi said.
The memo of understanding Carney signed with Alberta Premier Danielle Smith earlier in the day commits Ottawa and Alberta to working toward building an oil pipeline to the West Coast, throwing the future of the B.C. coastal tanker ban into question.
The document states Ottawa's commitment hinges on the pipeline being approved as a project of national interest, but affirms that changes could be made to the tanker ban to enable oil exports to Asian markets.
Guilbeault was federal environment minister to former prime minister Justin Trudeau for years, and served as the chief salesperson and defender of the contentious consumer carbon tax.
He quickly became a target for Conservative critics and Alberta politicians — especially Premier Smith, who branded him as a radical climate activist out to block oilsands projects and associated employment.
Guilbeault introduced Canada’s first emissions reduction plan — effectively a road map for reducing greenhouse gas emissions by 40 per cent below 2005 levels by 2030.
Guilbeault came to politics as a lifelong, prominent Quebec environmental activist, and co-founder of Quebec’s largest environmental group, Équiterre, in 1993.
Two decades ago, when he was a Greenpeace activist in his early 30s, Guilbeault climbed Toronto’s CN Tower with another activist in a PR stunt, where they set up a banner that accused Canada and the U.S. of being “climate killers.”
The feat was done to protest Ottawa failing to ratify the 1997 Kyoto Protocol climate accord. Guilbeault ultimately pleaded guilty in an Ontario court to public mischief.
His official federal government biography celebrates the event, and points to his earliest acts of protest: at age five, he climbed a tree behind his home to protect it from real estate developers who wanted to cut it down.
Guilbeault was first elected as Liberal MP for Laurier—Sainte-Marie in 2019 and first served in cabinet as heritage minister, where he ushered in major reforms to Canadian broadcasting policy.
He moved to the environment portfolio after the 2021 election and helmed the ministry until 2025.
This report by The Canadian Press was first published Nov. 27, 2025.
— With files from Nick Murray, Catherine Morrison and David Baxter
