Steven Guilbeault will run for the federal Liberals in Montreal

Click to play video 'High profile environmentalist to run for Liberal Party of Canada' High profile environmentalist to run for Liberal Party of Canada
WATCH: After months of speculation, environmental activist Steven Guilbeault announced on Friday that he will be running for the Liberal Party of Canada in the Montreal riding of Laurier-Ste-Marie. As Global's Brittany Henriques reports, it's a seat held by the NDP since 2011.

Renowned Quebec environmentalist Steven Guilbeault has officially thrown his hat into the ring for the upcoming federal election.

The founding member of Équiterre, one of the province’s largest environmental organizations, announced on Friday that he will seek the federal Liberals’ nomination in Montreal’s Laurier-Sainte-Marie riding.

“For me, the decision to jump into the political arena is the logical conclusion of 25 years of engagement,” he said.

READ MORE: Trans Mountain pipeline expansion gets green light to proceed

Guilbeault said he has worked his whole life with people across Canada who care deeply for the environment. The Justin Trudeau government has climate change at the heart of its mandate, he added.

WATCH: Environmentalist Steven Guilbeault is officially running for the federal Liberals in Montreal. He hopes to represent the Laurier-Sainte-Marie riding.
Click to play video 'Steven Guilbeault to run for federal Liberals' Steven Guilbeault to run for federal Liberals
Steven Guilbeault to run for federal Liberals

Despite his opposition to the Trans Mountain pipeline, he says the Liberal Party has been the most progressive in terms of climate change action and the party reflects his overall values.

Story continues below advertisement

“If the Liberals form the government this fall, Canada will have a real climate change plan, a real plan for the environment,” he said. “If the Conservative government wins, we will not. It’s that simple.”

The move comes after rumours swirled for months that Guilbeault would make the leap into politics. When he announced he was leaving Équiterre in October 2018, he downplayed the idea that he would join a party but was careful not to rule out running for the upcoming federal election.

READ MORE: Steven Guilbeault leaves environmental group Équiterre

During his career, the longtime environmentalist has also worked for Greenpeace Canada.

The Laurier-Sainte-Marie riding is an NDP stronghold in Montreal — and a riding the Liberals haven’t been able to snag in nearly three decades.

Former Bloc Québécois leader Gilles Duceppe represented the riding for years until the NDP swept through the province with an orange wave and Hélène Laverdière won in 2011. She announced last year she will not seek re-election.

Nima Machouf, the new NDP candidate for the riding, said Guilbeault’s choice to join the Liberals is a bad one in light of the Trudeau government’s decision to approve the Trans Mountain pipeline expansion.

“I think for a person who has spent more than half of his life working with and thinking of the planet and environment, it’s a very bad decision,” she said.

Story continues below advertisement

WATCH: Trans Mountain pipeline expansion approval

Click to play video 'Trans Mountain pipeline expansion approval' Trans Mountain pipeline expansion approval
Trans Mountain pipeline expansion approval

Guilbeault, for his part, maintains he’s determined to fight climate change in Canada alongside the Liberals — even if he disagrees with the expansion.

“When I look at everything they have done over the last four years and the fight against climate change, this has been one of the most proactive governments if not the most proactive government we’ve seen,” he said.

—With files from Global News’ Brittany Henriques and the Canadian Press