In a shocking turn around, François Legault’s Quebec will intervene on behalf of Saskatchewan to challenge the federal carbon tax in the supreme court alongside Premier Scott Moe.

Quebec would be the latest province to join Ontario, Manitoba, New Brunswick, Alberta and Saskatchewan to challenge the federal government’s levy as unconstitutional.

The provincial government announced the decision in a press release earlier today.

“The purpose of this intervention will be to ensure the legal and economic security of the Quebec emission cap and trading system (SPEDE) by ensuring the jurisdiction and jurisdictional autonomy of Quebec in this area,” stated the press release.

Originally, Quebec praised the federal government’s decision to implement a carbon tax but in what is a total reversal of opinion, the province has now expressed its total opposition to it on the basis of constitutional rights and the security of the province’s cap-and-trade system.

In 2012, the province had introduced a cap-and-trade plan to fight climate change which costs polluters a little over $20 a tonne. Due to this system, Quebec was able to avoid having the federal government’s ready made carbon tax implemented in the province.

“It is important for our government to intervene in this debate to ensure that Quebec can defend its position and that it be heard before the Supreme Court of Canada. The Quebec government has shown real leadership in implementing its own carbon exchange,” said Sonia LeBel, Minister of Justice and Attorney General of Quebec.

“He considers that he had acted within his field of competence and will reiterate in his speech the importance of protecting the autonomy of the provinces and their ability to decide for themselves their own fields of competence.”

According to the Montreal Economic Institute the province of Alberta, which recently abandoned its own carbon tax, would have to pay 50% more than Quebec on carbon.

In May, Saskatchewan lost its battle against the carbon tax in the Court of Appeal after judges ruled that the federal government’s decision was constitutional, but now the case has been taken all the way to the supreme court.