The Supreme Court of Canada will rule today on Quebec's effort to preserve data from the long-gun registry — data the federal government wants destroyed.

With its 2012 law, the Ending the Long-Gun Registry Act, the Conservative government demanded the destruction of all information that was stored to date on long-gun certificates and licences in Canada.

The Quebec government objected when the bill was tabled in 2011, saying it wanted to set up its own registry and planned to use the data that had already been collected.

Quebec won a challenge in Quebec Superior Court in 2012. The judge ruled that the section of the act that called for the destruction of records interfered with the province's right to exercise powers within its own jurisdiction, and was therefore unconstitutional.

But the Quebec Court of Appeal later overturned that decision, ruling the federal government has the jurisdiction not only to legislate a gun registry, but also to eliminate one.

The court considered whether the destruction of the information about Quebec long-gun owners interfered with provincial jurisdiction under the Constitution.

The Quebec government has argued the gun registry was embarked upon as a joint federal-provincial project in the spirit of co-operative federalism. And it says maintenance of the project was done to the benefit of both levels of government.

The long-gun registry was created under a Liberal federal government, in part as a response to public concern following the shootings deaths at Montreal's Ecole Polytechnique in 1989.

Conservative narrative

One way or another, the ruling will play into the Conservative narrative on gun control and the rights of gun owners.

Earlier this month, Prime Minister Stephen Harper once again played to his base by saying people in remote areas need guns, because they provide "a certain level of security when you're ways away from police, immediate police assistance."

Some have criticized those remarks as promoting vigilante justice — although the government has strongly denied that.

If the court finds in Ottawa's favour, the government will take it as vindication of its authority over gun control. If the court rules in Quebec's favour, it will be yet another ruling that undermines the Conservative legislative agenda.

But it would also give the government an opportunity to rail against the court's decisions on a topic that's proven to be a vote-getter for the Conservatives.