The federal carbon tax is going on trial at the Supreme Court of Canada this week.

The court will hear appeals in three separate cases to determine if the tax legislation is constitutional or if it encroaches on areas of provincial jurisdiction.

Appeals courts in Saskatchewan and Ontario upheld the law, while the Alberta Court of Appeal ruled it unconstitutional.

The Supreme Court case could be a make-or-break decision for one of the central pillars of the Liberal climate agenda.

It accounts for as much as 40 per cent of the cuts to greenhouse-gas emissions needed to meet Canada’s obligations under the Paris climate change agreement.