More than a dozen current and former members of the Prime Minister’s Youth Council are calling on Justin Trudeau to halt the federal government’s announced $4.5-billion buyout of the Trans Mountain pipeline from Kinder Morgan.

In a sign-on letter, the council members write of their “immense disappointment” in the decision, arguing that it violates assurances Prime Minister Justin Trudeau made to protect the coast of British Columbia, jeopardizes the success of international climate change pacts such as the Paris Agreement and violates the Liberal Party’s promises to renew nation-to-nation relationships with indigenous peoples.

Habon Ali, a current member of the council and student of environmental studies at the University of Toronto, said that Canada is lucky to have a government that is interested in environmental issues, but added that it missed an opportunity “to be a leader on this file.”

“Oil dependency is a reality and I understand that it’s a big part of our economy,” Ali told CTVNews.ca. “But where will we be in 50 years or 100 years?”

“The decision to buy the Trans Mountain pipeline project calls into question your commitment to young Canadians,” the letter says. “It is youth who will be disproportionately affected by the devastating consequences of a warming world, and yet you did not sufficiently consult before taking a decision that has profound and irreversible consequences for youth in Canada and around the world.”

The letter asks the prime minister to cancel the buyout, promise not to escalate violence or use militarized police forces to confront protesters and to hold a special open session with young Canadians on the buyout and energy issues more broadly.

“We are asking you to be the leader you were entrusted to be: honourable, ethical and courageous enough to act accordingly,” the letter says. “Choose a path of fiscal prudence, social and cultural healing, and sustainable growth for Canada, and you will begin to write a future that young people will be proud to read about.”

In a statement to CTVNews.ca, a PMO spokesperson said Trudeau is “proud to have a Youth Council that has voices from across the political spectrum.

“It is heartening to see young Canadians engage on political issues that affect them and become involved in the democratic process,” Chantal Gagnon wrote in an email.

Gagnon said the federal government is committed to protecting Canada’s oceans and marine life, and working with Indigenous and coastal communities to make that happen.

“The Prime Minister always appreciates input from the Youth Council and will continue to engage with them on issues that matter to Canadians,” she wrote.

The federal government announced in May that it had negotiated a $4.5-billion price to buy the stalled Trans Mountain pipeline, which runs from Edmonton to Burnaby, B.C., from Houston-based Kinder Morgan. The expansion of the existing pipeline would triple the amount of oil transported from 300,000 barrels a day to 890,000 barrels a day, and allow Canada to export its oil to markets in Asia.

The prime minister and others have argued that the pipeline is in the “national interest” and that its expansion will bring needed jobs to the area and help to boost the economy.

But some lawmakers, environmentalists and various indigenous groups have panned the expansion, arguing that a pipeline spill could permanently damage the B.C. coast and that indigenous people have not been properly consulted on the decision.