Calgary city council has voted unanimously to formally oppose Quebec's Bill 21, legislation that bans public sector employees from wearing religious symbols.

Experts say the notwithstanding clause does not necessarily provide a blanket shield against charter challenges, nor does it prevent the federal government from pursuing other legal avenues.

The NDP ad, which was voiced completely in French, aimed to gather supporters in the francophone province. Singh has long been a critic of Quebec's secularism law, Bill 21, which prevents the wearing of religious wear, including that of turbans, in positions of authority.

The two premiers are attending an annual meeting of provincial and territorial leaders in Saskatoon, where Brian Pallister says he will express his concerns about the new law.

Justin Trudeau on Bill 21: "We do not feel it is a government's responsibility or in a government's interest to legislate on what people should be wearing."

Bill 21, a controversial legislation that makes it illegal for public sector employees to work while wearing religious symbols, was passed Sunday night.

With less than two weeks left in the spring session, the Liberal Opposition says Simon Jolin-Barrette's juggling act is hindering important debate at the National Assembly.

The Coalition Avenir Québec denies that its secularism bill and religious symbols ban are causing any division in Quebec society.

As the hearings into the Coalition Avenir Québec's proposed bill on religious neutrality continues, Premier François Legault was asked to answer an existential question during question period on Wednesday.