MONTREAL -- A coalition of federal, provincial and municipal politicians added their voices to those opposing Quebec's proposed secularism bill on Sunday as they joined community leaders and citizens in denouncing the legislation as discriminatory and unconstitutional.

A few hundred people gathered in front of a community centre in the Montreal-area Cote-Saint-Luc suburb for a protest against Bill 21, which would prevent many state employees, including teachers and police officers, from wearing religious symbols on the job.

Anthony Housefather, who was one of five Liberal MPs to attend, said politicians have a responsibility to stand up against a bill that threatens fundamental rights and freedoms.

"As your Member of Parliament, if there is ever a law that threatens the rights of any of my constituents, it is my obligation to come out and protests against it, no matter what level of government is proposing it," he said.

Housefather took particular aim against Quebec Premier Francois Legault's choice to invoke the notwithstanding clause to block potential legal challenges, saying the population at least has a right to know if a bill is unconstitutional.

He said that while he doesn't believe the clause should be used at all, it's especially inappropriate to use it preemptively.

"If a government wants to let a bill proceed through the courts, find out it's unconstitutional, and then with the population knowing it's unconstitutional knowing it's unconstitutional choosing to use the notwithstanding clause to use it, then that's their prerogative and they'll take the political hit," he said in an interview on the edges of the demonstration.

"But they shouldn't be shielded from having a court judgment about a law."

Many attendees, including provincial legislature member David Birnbaum, argued the effect of the Quebec government's proposed bill runs counter to the ideals of neutrality it claims to uphold.

"The idea of a neutral state is very clear," Birnbaum said.

"If I am wearing my kippah, if you are wearing your hijab, if you are wearing your mohawk punk haircut with five rings in your nose, the state is blind, and your right to be part of it in every way is sacred."

Speaking at a different Montreal event on Sunday, Legault reminded reporters that the consultations on the bill are still ongoing and the government is "open to all kinds of suggestion."

But he said the current bill is reasonable and already includes compromises, such as the inclusion of a grandfather clause that would allow current employees to keep their jobs even if they wear religious symbols.

The protesters included the dean of McGill University's Law school, teachers, school board representatives, municipal politicians and citizens such as 13-year-old Zachary Richard, who stood with his mother waving a sign that read "Let us all be one, in our own way."

"There are a few teachers at my school who wear kippahs or hijabs, and I think that's good I respect it," Richard said. "I don't think Legault should take that away from us."

But one notable absence was that of Hampstead Mayor William Steinberg, who came under fire in recent days for likening Bill 21 to "ethnic cleansing, not with a gun but with a law."

Steinberg decided not to attend despite rejecting multiple demands to apologize, including from Legault and Prime Minister Justin Trudeau.

But Cynthia Carsley, a local resident who attended the protest with her husband, said she felt Steinberg's words were accurate.

"I think it's absolutely the correct term, because when you strip people of their right to wear the clothing that their religion dictates, it's terribly dictatorial," she said.

Carsley, who is Jewish and married to a Holocaust expert, said she feels the term can be expanded to encompass the Quebec government's actions even if no blood is being shed, saying actions that target minorities are a "slippery slope" that can precede larger-scale abuses.

Polls have shown a majority of Quebecers support the restrictions proposed in the bill, but it has drawn strong condemnation from groups representing minorities, women and human rights.

The protest in Cote-Saint-Luc was only the first of two that was scheduled to take place in Montreal on Sunday. A second event, this one a march through the streets of downtown, got underway shortly after 2 p.m.