Canada's top court has ruled the federal Impact Assessment Act (IAA), also known as Bill C-69, is on balance unconstitutional.

On Friday, five out of seven judges ruled the environmental scheme as too broad in its assessment of environmental impacts.

"Environmental protection remains one of today's most pressing challenges," said Chief Justice Richard Wagner. "To meet this challenge, Parliament has the power to enact a scheme of environmental assessment. Parliament also has the duty however, to act within the enduring division of powers framework laid out in the Constitution."

The bill, enacted by Parliament in 2019, provides a process for assessing the environmental impacts of designated energy projects. It also allows for more public consultation and participation in the assessment of any future energy projects.

The legislation's critics have called it the "No More Pipelines" bill. The province of Alberta sent it to the Alberta Court of Appeal, which ruled the legislation unconstitutional in 2022. Ottawa appealed the decision to the Supreme Court and arguments were heard last spring. Nine out of the 10 provinces oppose the scheme.

"The scheme's decision-making mechanism therefore loses its focus on regulating the federal impacts," Wagner said. "Instead it grants the decision maker a practically untrammelled power to regulate projects ... regardless of whether Parliament has jurisdiction to regulate a given physical activity in its entirety."

The designated projects section of the legislation, which includes projects set out under the regulations of the bill and those subject to ministerial orders, is the section the Supreme Court ruled as unconstitutional.

Alberta Premier Danielle Smith said she was extremely pleased with the Supreme Court decision.

鈥淚f you believe in fairness, common sense and the sanctity of the Canadian Constitution, today is a great day,鈥 said Smith in a press conference with reporters in Calgary. 鈥淭oday's decision significantly strengthens our legal position as we work to protect Albertans and all Canadians from federal intrusion into our provincial jurisdiction.鈥

However, the judgement does rule that sections 81-91 in the bill, which relate to the federal government's right to conduct impact assessments on projects carried out on federal land and impact federal jurisdictions, are constitutional.

In their dissenting opinions of the judgment, Justice Mahmud Jamal and Justice Andromache Karakatsanis argued that because the environment, by its very nature, is broad, there should be a level of flexibility afforded to regimes that regulate it.

On Friday, Environment and Climate Change Minister Steven Guilbeault said the federal government accepts the ruling and acknowledged the bill needs to be "tightened."

"We will now take this back and work quickly to improve the legislation through Parliament," Guilbeault said in a virtual press conference with reporters. "We will continue to build on 50 years of federal leadership in impact assessment."

In the drafting of new legislation of the IAA, Guilbeault said the federal government would follow the guidance from the court and collaborate with provincial and Indigenous leadership.

In Vancouver, Conservative Leader Pierre Poilievre also reacted to the ruling.

"Today we learned that the Supreme Court of Canada has found Justin Trudeau's no new pipeline anti-resource law unconstitutional," he said. "A Poilievre government will repeal this law entirely and replace it with one that consults First Nations, protects our pristine environment, but gets jobs approved."

Environment groups expressed their disappointment in the court鈥檚 advisory ruling.

鈥淭he federal government must move swiftly to restore the constitutional legality of the Act,鈥 reads a statement released by Environment Defence Canada. 鈥淔ederal oversight is crucial, given that environmental issues are not contained within provincial borders. And it鈥檚 especially crucial when provinces aren鈥檛 taking environmental responsibility seriously or, as the case may be, are outright hostile towards environmental protection.鈥