The Supreme Court of Canada ruled against the federal government’s impact assessment law on Friday, with five out of seven judges finding most of it to be unconstitutional because it ultimately seeks to regulate activities within provincial jurisdiction.

Chief Justice Richard Wagner, writing for the majority, said the law as written is aimed at regulating activities that are provincial business, instead of being aimed at environmental effects that are within Ottawa’s power to regulate.

“Even if this court were to accept Canada’s submission that the defined ‘effects within federal jurisdiction’ are within federal jurisdiction, these effects do not drive the scheme’s decision-making powers,” he wrote in the 204-page opinion released Friday.

Wagner went on to say that the impacts considered in the legislation previously known as Bill C-69, which included a range of environmental and social factors as well as climate change, were “overbroad.” 

Two judges, however, dissented, saying the law was constitutional.

Enacted in 2019, the law lists activities that trigger a federal impact review.

Alberta opposed it, arguing the law gives Ottawa power to stick its nose into provincial matters such as resource development. In 2022, it asked the Alberta Court of Appeal for a legal opinion.

The Appeal Court, in a strongly worded 4-1 decision, called the law an “existential threat” to the division of powers in the Constitution and a “wrecking ball” on the rights of Alberta and Saskatchewan. 

The Impact Assessment Act is now the second such piece of legislation to be thrown out by the courts. 

In 2016, the Federal Court of Appeal struck down assessment legislation passed by the Conservative government of Stephen Harper.