As the Quebec government prepares to table its secularism bill, constitutional experts are raising concerns about Premier François Legault's reported plans to pre-emptively invoke the notwithstanding clause to ensure public workers in positions of authority are banned from wearing religious symbols.

Robert Leckey, dean of McGill University's law faculty, said doing so would effectively make it impossible to challenge the constitutionality of the legislation.

"It really immunizes the law from the more obvious charter challenges," Leckey said in an interview.

Montreal's La Presse newspaper reported last week that a provision to invoke the clause could be written into Bill 62 itself.

The notwithstanding clause, officially called Section 33 of the Charter of Rights and Freedoms, allows provincial or federal authorities to override certain sections of the charter for a period of five years.

Sources told Radio-Canada earlier this week the bill will go further than originally expected. New teachers, as well as school principals, would be subject to the ban, which would also apply to lawyers, judges, police officers, courthouse constables, bodyguards, prison guards and wildlife officers.

'Collective rights'

Civil rights groups have already vowed to challenge the legislation, but Legault has repeatedly said he's prepared to use the notwithstanding clause to impose the ban.

He said so again on Tuesday.

"It's not a small thing. It's a big decision. But sometimes, in order to protect collective rights, we have to use it. I think we have to protect our collective identity," Legault said, pointing out the clause has been invoked numerous times by different premiers.

"To separate religion and politics is important in Quebec."

The Quebec government's intention of regulating religious clothing has already drawn protests, including this one last fall in Montreal. (Graham Hughes/Canadian Press)

The bill by his Coalition Avenir Québec government will be the fourth successive attempt at laying out a framework for religious neutrality in the province, following previous efforts by the Jean Charest Liberals, the Parti Québécois under Pauline Marois and the Liberal government of Philippe Couillard.

The most controversial sections of Couillard's legislation are still before the courts after being subjected to a charter challenge.

But given the province's long history of debate about religious neutrality, Leckey is skeptical that moving quickly will allow the CAQ government to settle the matter once and for all.

"I just don't think it's the case that it will put a lid on these things," he said.

"I think there will be a messiness in applying the law."

Rarely used, except in Quebec

Political leaders across the country have been reluctant to use the notwithstanding clause, which is viewed by many as politically perilous. It has only been invoked three times outside Quebec.

"The view was that this would be a clause used infrequently and in very specific circumstances. I'm not sure whether that is what's qualifying the use of it today," said James Kelly, a constitutional expert and political science professor at Concordia University.

The clause is more commonly invoked inside Quebec, where it has served as both a means of symbolic resistance and as a tool to defend Quebecers' collective identity.

The most controversial use of the notwithstanding clause was in 1988, when then-premier Robert Bourassa used it to override a Supreme Court ruling on minority language rights, passing a law requiring outdoor commercial signs to be in French only.

The possibility of the clause being invoked pre-emptively harkens back to how a former Parti Québécois government used it.

Former Quebec premier Robert Bourassa, seen here in June 1990, used the notwithstanding clause in 1988 to override minority language rights in Bill 178, which required outdoor commercial signs to be in French only. (Paul Chiasson/Canadian Press)

Between 1982 and 1985, the PQ objected to the terms of the new Canadian Constitution by including a notwithstanding clause in every piece of legislation it introduced.

Philippe-André Tessier, the head of Quebec's Human Rights and Youth Rights Commission, said the CAQ's proposed bill should be put to a debate at the National Assembly.

"The commission believes that it's only in exceptional circumstances that the notwithstanding clause should be used," he said.