The party says it wouldn't hesitate to use the constitutional notwithstanding clause to override any legal argument that the plan violates the Canadian Charter of Rights and Freedoms.
In fact, the pro-independence party appears to relish the prospect of a fight against federal institutions. The party has already said that if it wins the Sept. 4 election it will pick battles with the federal government and use each example to argue its case for independence.
"Our boss is not the Supreme Court of Canada — our boss is the will of the people of Quebec," said Jean-Francois Lisee, a Parti Quebecois candidate and longtime party adviser, in an interview.
"We do not want to legislate while taking into account Canadian judges. We will legislate considering the interests of Quebecers."
The PQ plan would forbid employees in public institutions from wearing overt religious symbols. The policy would apply to kippahs, hijabs and turbans but not to necklaces, like the crucifix.
Lisee noted that, after the Constitution was patriated in 1982, then-premier Rene Levesque systematically invoked the notwithstanding clause on every piece of legislation tabled in the legislature, as a symbolic gesture of defiance against Ottawa.
Lisee said a future PQ government could try to invoke the clause pre-emptively when it introduces its proposed Charter of Secularism, or it could also use it afterward if a court strikes down the plan.
"We'll have no hesitation to use the notwithstanding clause as a preventive measure," Lisee said.
"I'm not saying we will do that. I'm saying we're not shy to use the clause because our purpose is to affirm the will of Quebecers."
One constitutional expert says the PQ plan would be shredded up in court.
Julius Grey used the example of doctors with religious headwear and said that if they one day challenge the PQ proposal, they will win.
"Imagine the absurdity of saying that we have the best surgeon in Quebec, but he can't operate in Quebec because he's not permitted to wear his kippah, turban or scarf," Grey said in an interview Thursday.
"I think a doctor would succeed — I think there's no reason for a doctor not to wear a turban, kippah or scarf."
Grey cited jurisprudence that could be used to knock down the PQ proposal, including the famous case of turbans in the RCMP.
He said a future PQ government would then have only one tool left in its legal arsenal — the notwithstanding clause, which allows legislation to temporarily override parts of the Constitution.
But Grey says that move would be a political hornet's nest.
"The notwithstanding clause cannot be applied without causing years of contestation," he said. When a government uses the clause to protect legislation, it expires after five years. That would force a future government to go through the process of re-introducing the controversial law.
The Quebec constitutional expert said the notwithstanding clause is there for extreme situations and emergencies — not for a doctor in a yarmulke.
Lisee cautioned against any rush to judgment. He said the plan will be debated and put together carefully.
"We are not dummies. Nobody will be at the doors of Jewish hospitals taking kippahs off of doctors' heads. That's not the case," Lisee said.
"We're going to have a debate about what institutions will be covered. That's wide open for discussion, in particular for hospitals and institutions that have a strong patrimonial religious history...
"There is not a steamroller effect — there are going to be a lot of exceptions, we know the culture, we know the history. This will not be a one-size-fits-all, in particular in the health sector."
Another constitutionalist was more equivocal than Grey.
Stephane Beaulac of the Universite de Montreal agreed the issue could end up in the Supreme Court. But he said the verdict is far from guaranteed.
"The outcome of any case before the courts, in my opinion, is very uncertain: I would put it at 50-50," Beaulac said.
Beaulac said the courts would likely decide on whether a limit on freedom of religion is justifiable in a free and democratic society.
Beaulac also differed with Lisee, questioning whether it would be legitimate to invoke the notwithstanding clause — Section 33(1) of the Charter of Rights — pre-emptively, before the issue had even been heard in court.
"You need to wait for the court decision. Then you go back (and re-introduce the law)," he said.
The PQ is leading in the public-opinion polls with a provincial election less than three weeks away. Leader Pauline Marois revealed Thursday that she has had a transition team in place for several weeks.
Also Thursday, Premier Jean Charest warned that the apparent split in the non-separatist vote risks allowing the PQ to waltz up the middle.
Charest said that if people want to avoid another referendum, and the economic uncertainty that comes with the sovereignty debate, they need to rally behind one party and support his Liberals.
The latest polls suggested the Liberals and Coalition party (CAQ) were fighting for second place, pointing to an easy PQ win despite its relatively weak overall support in the low 30s.
"We're telling people who are making a choice on Sept. 4 that if they vote for the CAQ they'll wake up the next morning with a very nasty surprise. They risk encouraging Ms. Marois and getting stuck with a referendum," Charest said.
"In this campaign, supporting the CAQ is supporting Pauline Marois. Voting CAQ means getting the PQ."
With an eye on the Quebec election, Grey said the opinion of the majority should not be used to determine the rights of minorities.
Grey added that there might be some cases where wearing religious symbols could be forbidden, like for judges or Crown prosecutors.
A court might find it "reasonable and proper" to legislate clothing for judges and other people whose neutrality is central to their job, Grey said.
The Montreal lawyer has in the past successfully argued landmark constitutional cases against Quebec's language law, and against a school's decision to forbid a Sikh boy from wearing the kirpan dagger.
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