It might be the last straw for the federal government’s prohibition of single-use plastics.

On Thursday, a federal judge struck down the government’s categorization of plastic items as “toxic”, saying it was both irrational and unconstitutional.

According to the Canadian Environmental Protection Act, the federal government is only authorized to enforce environmental regulations on substances explicitly designated as toxic.

A federal judge concluded that the broad classification of all plastics as toxic by the federal government could upset the balance of federalism, as it fails to confine regulation to plastics that genuinely present environmental risks.

In a joint statement, Premier Danielle Smith, and Alberta Environment Minister Rebecca Schulz emphasized that the court also reminded the federal government that ‘cooperative federalism’ recognizes that the provincial and federal governments are equal in status, adding that provincial governments are not subordinate to the federal government.

The Premier and Minister also stated that “a federal head of power cannot be given a scope that would eviscerate a provincial legislative competence.”

The court’s decision raises questions about the federal government’s ability to proceed with an upcoming ban on plastic bags, straws, and food service items set for December 20th.

Federal Environment Minister Steven Guilbeault said that his Ministry is seriously considering appealing the ruling.