Alberta's highest court ruled on Tuesday that a Canadian law assessing how major infrastructure projects like pipelines impact the environment is unconstitutional because it interferes with the power of the provinces.
The Alberta Court of Appeal said the Impact Assessment Act (IAA), passed in 2019, was a "classic example of legislative creep" and intrudes on provincial jurisdiction.
The decision is a win for Alberta Premier Jason Kenney and his United Conservative Party government, which brought the legal challenge against the act.
However, the federal government plans to appeal the decision in the Supreme Court of Canada.
"Our view is the legislation is constitutional and we will be appealing," Natural Resources Minister Jonathan Wilkinson told reporters.
Kristen van de Biezenbos, associate professor of law at the University of Calgary, said she expected the Supreme Court to reverse the Alberta Court of Appeal's decision, much like it upheld the legality of the federal carbon-pricing act last year.
"There's nothing different enough about what's in this law to justify finding it unconstitutional," she said.
The IAA, formerly known as Bill C-69, was passed by Prime Minister Justin Trudeau's Liberal Government in a bid to streamline and restore trust in the environmental approval process for major projects.
But it stirred fierce opposition in Canada's main crude-producing province Alberta, where critics said it would deter investment by giving the federal government too much power to kill projects.
Kenney, who has long argued that Alberta is treated unfairly by Ottawa, welcomed the court decision on Twitter.
"An historic victory, and central part of our strategy to fight for a fair deal!" he wrote.
(Additional reporting by Steve Scherer in Ottawa; Editing by Cynthia Osterman)