What happens when a provincial government defies a federal law? We're about to find out

When Environment Minister Steven Guilbeault suggested it was "immoral" for the government of Saskatchewan to deliberately defy the federal carbon pricing law, the allegations of hypocrisy followed quickly.

Had Guilbeault himself not been arrested for breaking the law? Hadn't he proudly climbed the CN Tower in 2001 to protest Canadian climate policy?

Conservative Leader Pierre Poilievre posted a picture of Guilbeault being taken into custody by police in 2011 and later asserted that what was really "immoral" was the Liberal government increasing the carbon tax while also flying to international summits.

But there's much more at stake here than whether Guilbeault has the standing to lecture anyone on the rule of law.

As an environmental activist with Greenpeace in 2011, Guilbeault indisputably broke the law when he scaled the CN Tower in Toronto. He was arrested, charged and punished — receiving a year's probation and a fine. (He also climbed atop the house of Alberta's then-premier Ralph Klein to install solar panels in 2002. Charges reportedly were not pursued on that occasion.)

Guilbeault might defend what he did as an act of civil disobedience. Others might describe it as reckless and dangerous. 

But when he broke the law, he did so as a private citizen. And there is a big difference between a private citizen consciously defying the law and a government consciously defying the law. The latter, operating with democratic authority and responsibility, is empowered to enforce laws.

Saskatchewan's government argues that it's fair for it to stop charging the carbon tax on natural gas because the federal government decided last fall to exempt home heating oil from the carbon tax for the next three years — a move that was widely seen as an attempt to address public concerns in the Atlantic provinces.

The wisdom and logic of that Liberal decision is at least debatable. And having introduced inconsistency into its carbon-pricing policy, it can be argued the Liberal government invited claims of unfairness. Saskatchewan Premier Scott Moe is hardly alone in complaining about the Liberal government's course of action.

But when a provincial government has a problem with a federal law — a situation that has occurred once or twice in Canada's history — it has valid recourse to the courts, or the ballot box. It can ask judges to overturn the law, or it can ask voters to defeat candidates representing the federal party that introduced the law.

When a government is willing to defy a law, it's fair to ask what message its constituents should take from that. Presumably, the government of Saskatchewan does not want residents of the province to believe its own laws are optional.

"Well, I certainly wouldn't advise anyone to follow what we're doing," Dustin Duncan, the responsible minister in Saskatchewan, told CBC's Power & Politics last week. "But that's how serious we take this in Saskatchewan."

Of course, when people break the law they generally run the risk of being arrested, as Guilbeault learned in 2001. And Duncan has acknowledged there could be "consequences" for his government's actions.

But Prime Minister Justin Trudeau's government seems disinclined to make this a criminal matter.