Environmental groups in Canada fear endangered orcas could become a casualty of Mark Carney’s push for a new oil pipeline, as the rush to develop fossil fuel infrastructure collides with laws meant to protect threatened species.

The decades-long tragedy of the critically endangered southern resident orcas has become emblematic of ecosystem in crisis. But fishermen, whale-watching companies and the marine transport industry have long feuded over bears the most blame.

The southern resident orcas can only survive on a diet of chinook salmon, a species that itself is in steep decline. While there were more than 200 at the beginning of the 20th century, nowadays only about 70 swim the waters between British Columbia and Washington state.

Environmental groups have raised the alarm over increased ship traffic along the south-west coast of British Columbia – the result of a busy Trans Mountain oil pipeline that terminates near Vancouver and a new liquefied natural gas (LNG) terminal further north.

On Friday, Carney announced plans for a new oil pipeline from Alberta to the Pacific coast, with construction expected to begin by fall of 2027.

And a new policy discussion paper has raised fears that in pursuit of the project, the federal government might bypass legal protections for the orca.

The document, titled Getting Major Projects Built in Canada, called the process for building mines, ports, airports, pipelines “slow, expensive, and confusing”, and suggested a number of changes to existing rules to fix this issue.

But one part of the paper, which proposes exempting major projects from the “jeopardy test for species at risk” has caught the eye of environmental advocates.

Part of Canada’s endangered species legislation forces regulators ask whether an project would jeopardize the survival or recovery of a protected species.

“In practical terms, this provision is intended to prevent projects from pushing endangered species into extinction. Weakening this safeguard has direct implications for southern resident killer whales and their protection under [the species at risk act],” said Misty MacDuffee, a biologist at Raincoast Conservation Foundation. “As the federal government has acknowledged in its imminent threat determination, these whales face extinction under the existing conditions.”

The proposed changes are open to public comment until 9 June.

The development, first reported by the Toronto Star, prompted the federal government to respond that the reporting “could not be further from the truth”.

The transport minister, Steven MacKinnon, pointed to recent investments by his government to protect at-risk whale populations, including C$91.3m to address other threats to the southern resident orca population. The government is also changing the laws around how much distance ships must give the whales, raising it from 200 metres to 1,000 metres to minimize physical and acoustic disturbance from vessel traffic.

“We would not take any actions that would undermine these important strategies and substantial investments. Our approach to assessments isn’t about cutting corners, but improving coordination, efficiency, and long-term planning resulting in faster decisions, without weakening oversight or standards,” he wrote in a statement.

But critics says that while the government has made key promises to protect whales, they also appear to be looking for a carve-out by exempting projects of national interest from stringent reviews where endangered species might be affected.

After the new pipeline deal was confirmed, environmental groups swiftly condemned the agreement.

“Recovery [of the orca population] requires improvements in habitat quality, including reductions in underwater noise and disturbance. Weakening the protective provisions of [endangered species laws] to enable projects that worsen these conditions would push southern residents closer to extinction,” said MacDuffee.

Environmental law charity Ecojustice said the move “jeopardiz[ed]” Canada’s ability to protect whale habitats.

“No project that threatens the extinction of iconic southern resident killer whales and puts communities’ health at risk could be ‘nation building’. Increasing tanker traffic in the already busy Salish Sea ups the risk of small and large oil spills and will also increase ocean noise – pushing the critically endangered southern resident killer whales further towards extinction. Expanding the Trans Mountain pipeline has overwhelmed the modest noise reductions put in place to protect whales from pre-pipeline expansion levels of shipping noise,” director Margot Venton said in a statement.

“Experts have been unable to find a way to offset the noise from increasing tanker traffic. These whales cannot handle any more tankers in their habitat.”

In the past, threatened or endangered species have delayed construction of major projects. When the government was trying to build the TransMountain pipeline, a rare species of humming bird temporarily halted work.

But the effectiveness of Canada’s species at risk laws have also been called into question, especially when the requirements clash with lucrative industries.

Successive environment ministers have declined to designate chinook salmon as a species at risk – largely over the implications such a decision would have for the fishing industry.

Nature Canada, one of the country’s oldest conservations groups, said it was calling on supporters to urgently contact lawmakers to vote against any fast-tracked legislation, warning it could lead to zones of “environmental lawlessness”.

“The effort to redefine environmental responsibility as mere ‘red tape’ is dangerously short-sighted,” Akaash Maharaj, director of policy at Nature Canada, said in a statement. “Nature is not an impediment to economic development; environmental assessment is the ‘credit check’ before we write the loan. It is due diligence, fiduciary responsibility, and the only way to build prosperity that endures.”