Premier Brad Wall, as well as Saskatchewan Party leadership hopefuls, have said they'll fight a federally-imposed carbon tax in court if need be.

A report by constitutional law expert Bryan Schwartz for Manitoba Premier Bryan Pallister says the federal government would have the upper hand in such a legal battle.

However, the report did say provinces might have some wiggle room to adopt a carbon tax with a lower rate if it is equally successful at reducing emissions as what the federal government is looking to impose.

The federal Liberals are looking for provinces to move to a $50-per-ton levy by 2022, starting with a $10-per-ton levy in 2018.