The Quebec government can't "with a straight face" claim its new religious symbols law won't have any harmful effects, a lawyer for two civil rights groups told a Superior Court justice Tuesday.

Catherine McKenzie made the comment as she asked the court to freeze the most controversial sections of the law. Tuesday's hearing in Montreal is the first legal test of Bill 21 since it became law last month in the face of widespread opposition.

The legislation bars authority figures, including public school teachers, from wearing religious symbols at work.

A motion filed by the National Council of Canadian Muslims and the Canadian Civil Liberties Association asks the court to issue an injunction pending a more complete review of the law's constitutionality.

Courts, though, are reluctant to impose injunctions on recently passed legislation. "We know what we're asking you to do is hard," McKenzie said to Justice Michel Yergeau.

'Real people being affected'

Just moments before, she had sought to dismantle the Coalition Avenir Québec's assertion that Bill 21 causes no irreparable harm — among the criteria for granting a temporary injunction.

McKenzie highlighted a series of written testimonies her clients had submitted to the court, including several from student teachers who now feel unable to pursue a career in Quebec.

"That's real people being affected by the law," McKenzie said, her voice rising as she delivered her argument.

Extra seating was needed in the packed courtroom Tuesday as lawyers for two civil rights groups asked a Superior Court justice to freeze the new law. (Ryan Remiorz/Canadian Press)

Then, pointing to the six government lawyers on the other side of the witness box, she asked "how can they say with a straight face" that the law was without negative consequences.

The hearing took place in a packed courtroom; a clerk brought in additional chairs to accommodate the overflow crowd, which included several women wearing the hijab.

Underlying the motion filed by the civil rights groups is the claim that Bill 21 is unconstitutional.

They can't, however, make that argument by appealing to the fundamental rights protected by the Charter of Rights and Freedoms.

The law makes use of the notwithstanding clause, which shields it from being challenged on grounds it violates certain sections of the charter.

In court, the civil rights groups argued there were at least three others ways the law could be considered unconstitutional.

It tramples on federal jurisdiction by imposing a moral view on how religion should be practised.

Its definition of a religious symbol is so vague that it will be applied arbitrarily.

It violates protections for minority rights that are embedded in the Constitution.

These three constitutional issues, McKenzie said, demonstrate the law raises serious enough concern to merit an injunction.

Lawyers for the government sought to refute these claims when they took the stand Tuesday afternoon.

Quebec is well within its rights when it comes to establishing rules for its civil servants, said Stephanie Roberts, who represents the provincial attorney general.

She also noted there are moral issues where the province's power to legislate is a given, such as gambling or liquor laws. Secularism, she said, is no different.

The most revealing exchange of the hearing, though, came when another government lawyer, Eric Cantin, addressed the concerns that had been raised about the law's consequences.

He said the law shouldn't be suspended pending what could be a lengthy consideration of its constitutional merits, citing the public interest in settling long-standing questions about secularism.

Justice Yergeau stopped Cantin to ask about the individuals affected by the laws. "In that time, people who in good faith sought to teach in Quebec … risk being deprived of that opportunity," the judge said.

People wait to enter a Montreal courtroom for a hearing challenging Bill 21, Quebec's religious symbols law. (Ryan Remiorz/Canadian Press)

Cantin responded by saying the collective good outweighed the effects on those who had included their testimonies in the motion.

"If law can't have an impact, then all laws would have to be suspended," Cantin said. He also asked Yergeau to "respect the choice that legislators made."

Yergeau gave McKenzie an additional five minutes at the end of the hearing to respond to the arguments put forward by the government.

She cited Cantin's assertion about the desires of the legislator, adding: "That's why we have courts."

Yergeau said he would try to render a decision within the next 10 days.