MONTREAL - While Prince Harry is shaking up the British monarchy, Canada's Supreme Court is being asked to throw out a law that modified the rules governing succession to the throne.
Two Quebec university professors have asked the country's highest court to hear their appeal of a ruling issued last October by the province's Court of Appeal.
In its judgement, the appeal court refused to declare unconstitutional a 2013 Canadian law modifying the rules governing who gets to be named King or Queen of the United Kingdom.
Laval University professors Patrick Taillon et Genevieve Motard filed their application at the end of December.
They say the law brings into question Canada's independence vis-a-vis the United Kingdom. In an interview, Taillon called it a "step backward."
Since the 1982 patriation of the Constitution, the British parliament has no right to legislate for Canada.
The Canadian law in question stems from a 2011 meeting of Commonwealth countries, where it was agreed that the rules governing succession to the British throne should be modified to allow a girl or woman to become Queen if she is the oldest heir to the throne. Historically, the oldest female heir would have been set aside in favour of her brother, even if he was born after her.
The changes needed to be adopted in separate laws in all 16 Commonwealth countries in order to come into effect.
Then-prime minister Stephen Harper did so with a federal law that was adopted in 2013.
But the Quebecois professors say changes to the monarchy cannot be made by simple legislation and instead require the consent of the provinces — something that would likely open up constitutional negotiations.
Quebec's appeal court ruled the law was valid and didn't require constitutional amendment. According to an unwritten rule in the Canadian Constitution, the King or Queen of the U.K. automatically becomes the sovereign of Canada, the court said.
But the professors say that unwritten law by definition doesn't exist, and accepting that the British monarch automatically becomes the King or Queen of Canada means accepting that British parliament can make decisions for the Canadian people, they say.
The appeal to the Supreme Court comes as Prince Harry and Meghan, the Duchess of Sussex, have taken up residence near Victoria, where they will give up public funding and try to become financially independent.
The couple are expected to spend most of their time in Canada, while maintaining a home in England near Windsor Castle, in an attempt to build a more peaceful life.
Taillon and Motard's battle has an unlikely ally: the Canadian Royal Heritage Trust, an association of monarchists agrees with the professors that the 2013 law is a violation of Canadian sovereignty, according to an intervention the group filed with the Supreme Court this week.
And while the group shares the same goal as the professors, their arguments are a little different. The trust says the 2013 law is "without effect" on the rules of royal succession in Canadian law, said Catherine Mathieu, a lawyer for the non-profit.
The Supreme Court could take several months before it decides whether it will hear the application for appeal.
