The Federal Court of Canada has been asked to void Ottawa’s recent changes to the Citizenship Act and declare it unconstitutional to revoke the citizenship of Canadian-born and naturalized citizens.

A day after the terror-linked gun shooting in Ottawa, constitutional lawyers argued in court on Thursday that Parliament has no legislative power to remove citizenship from individuals involved in armed combat against Canada, treason, spying and terrorism – unless the citizenship was obtained by fraud.

Bill C-24, the Strengthening Canadian Citizenship Act, was granted Royal Assent . In addition to raising the pass mark for citizenship exam and language requirement, the law also enables the government to revoke Canadian citizenship from dual citizens.

Constitutional lawyers said citizenship is fundamental to the constitutional order and the new revocation provision should have been made through a constitutional amendment with the support of seven provinces or 51 per cent of the population.

“Once you are a citizen, you are a citizen,” said lawyer Rocco Galati, who brought the case before the court along with lawyer Manuel Azevedo and the Constitutional Rights Centre Inc.

Calling Ottawa’s act “an indirect amendment to the Canadian constitutions,” Paul Slansky, who represented the constitutional rights centre, said the government only has the authority over “aliens and naturalization,” but does not have the power to strip the citizenship of Canadian-born people.

“The issue is whether it can be taken away without your consent with the natural-born and naturalized citizens,” he told Justice Donald Rennie. “The government does not have the authority to legislate on this issue.”

Government lawyers asked the court to dismiss the case because the revocation provision has yet to be enforced and any constitutional challenge should be dealt with when an affected individual brings a case forward.

Greg George, lawyer for the government, said the case is beyond the jurisprudence of the court and it should not “meddle” with the making of the law.

“The court has no business in getting into the legislative process of the government . . . until the ink is dry,” he said. He added that citizenship is not immutable and the United Kingdom also passed a law in 1983 so “not everyone born in the U.K. is a British subject.”

George said Canada’s Citizenship Act, since 1947, has always allowed the government to “denaturalize” someone engaged in combat against Canada or convicted of serious crimes, but no one ever challenged its constitutionality.

“Government passed legislation and it wasn’t challenged. It doesn’t mean it’s valid,” Slansky contended.

Justice Rennie reserved his decision.