MONTREAL - The Quebec national assembly passed a controversial religious neutrality bill Wednesday that will oblige citizens to uncover their faces while giving and receiving state services, triggering criticism the law targets Muslim women.

Quebec's two main opposition parties opposed the bill because they argued it didn't go far enough in restricting the presence of conspicuous religious symbols in the public sphere.

Tabled by Justice Minister Stephanie Vallee in 2015, Bill 62 is the governing Liberals' attempt to enshrine into law what is considered to be a fundamental Quebec value that the state should not promote religion of any kind.

It follows up on an election promise in 2014 to address the issue after the Parti Quebecois' own controversial secularism legislation - the so-called charter of values - died after the party was swept out of power that year.

The new law has two basic components: it bans the wearing of face coverings for people giving or receiving a service from the state and it offers a framework outlining how authorities should grant accommodation requests based on religious beliefs.

While the Liberal bill doesn't specifically mention the garb, it would prohibit the burka and niqab when people interact with the state, but it doesn't extend to other religious symbols as the PQ's charter did.

Premier Philippe Couillard said he expects some people to challenge the law, but he defended the legislation as necessary for reasons related to communication, identification and security.

"The principle to which I think a vast majority of Canadians by the way, not only Quebecers, would agree upon is that public services should be given and received with an open face," he said.

"I speak to you, you speak to me. I see your face. You see mine. As simple as that."

Vallee said guidelines on how to apply the law - notably criteria touching on reasonable accommodation - would be phased in by next June 30 after consultations.

Provisions regarding daycare workers will kick in by next summer to allow educators to get training, but the majority of the face-covering provisions will take effect once the lieutenant-governor rubber-stamps the law.

That means people who sit an exam will have to do so with their faces uncovered. Asked specifically about someone getting on a bus, Vallee replied that all such services must be offered or received without a face covering.

Advocacy groups and academics have said the law could be subject to legal challenge.

The National Council of Canadian Muslims, for instance, said it is "studying its options" with regard to a possible court challenge.

"In every piece of legislation, there's a risk of it being contested by those who don't agree with it," Vallee said. "We consider that this bill is solid, it's strong, it's a bill that's respectful of civil rights."

"We were very careful for the whole process to be respectful of the rights that are protected by the charters."

The face-covering ban initially only involved provincial employees when first introduced, but has since been amended to extend to the municipal level.

Montreal Mayor Denis Coderre said he remains very uncomfortable with the legislation, especially as it applies to the city's public transit.

"I don't understand why we have that kind of legislation, to be honest," Coderre told reporters Wednesday, noting no city employees wear niqabs.

He says Montreal stands to bear the brunt of the impact of the new law and reiterated concerns about city employees being forced to deal with tense situations, including having to decide whether women wearing Islamic face coverings should be able to use public transit.

"What does it mean? We have niqab police as bus drivers?" Coderre asked. "Will we refuse to provide them services if they are freezing with their children?"

Coderre said he has no problem with providing services with a visible face, but doesn't agree with the rest.

A spokesman for the union representing Montreal bus drivers, ticket takers and subway employees says it isn't interested in enforcing the law.

Ronald Boisrond of the Canadian Union of Public Employees says the union wants proper guidelines.

"Bus drivers don't want to have the responsibility of applying Bill 62 at this time," Boisrond said in an interview.

"We want the STM (transit authority) to give us clear guidelines about what we are supposed to do when the law is in force."

In Ottawa, NDP Leader Jagmeet Singh - who wears a turban in accordance with his religious faith - said he believes the law violates people's rights.

"I think fundamentally, we can't have the state tell people what to wear, what not to wear," he told reporters. "And that, particularly when it's applied in the way that will disproportionately impact some people."

He also suggested court challenges to the new law will be successful.

"There's laws that exist that are in place to protect the rights that everyone should be entitled to," Singh said.

"The human rights that people should have. Those are protected by existing laws in Quebec and I'm confident that the courts will continue to protect human rights."