Civil liberties advocates have launched a legal challenge over the constitutionality of Quebec's face-covering ban, arguing it "directly infringes on the freedom of religion of individuals."

The law passed last month requires people to uncover their face to receive public services under certain circumstances.

The legal challenge, filed Tuesday in Quebec Superior Court, contests a section of the province's religious neutrality law under both Quebec's Charter of Human Rights and Freedoms and the Canadian Charter of Rights and Freedoms.

"Such blatant and unjustified violations of freedom of religion, as well as of the quality guarantees of the Quebec and Canadian charters, have no place in Quebec or Canada," the plaintiffs argue in a court filing.

"These violations cannot be justified in Quebec's free and democratic society."

The National Council of Canadian Muslims, the Canadian Civil Liberties Association and Warda Naili, a Quebec woman who converted to Islam and wears a niqab, are also plaintiffs in the case.

She is referred to in the legal challenge by her birth name, Marie-Michelle Lacoste.

'Living in fear'

At a news conference, Naili said the legislation has emboldened anti-Muslim sentiment and she has been "living in fear" since the law was passed.

She said she would be "humiliated" if she were forced to remove her niqab for longer than "absolutely necessary."

Another woman named in the suit, Fatima Ahmad, said she has no problem removing her niqab briefly "in order to identify myself," as she does to get her student ID photo for the bus or if she is being examined at the doctor's office.

Fatima Ahmad, a McGill University student, says removing her niqab would make her feel like she's not acting in accordance with her religious beliefs. (Alison Northcott/CBC)

But the Montreal-born McGill University student said she is concerned the new rules will limit her ability to use public services, including the bus and the library, and attend university.

"I am devoted to wearing the niqab, so removing it in public would make me feel like I am not acting in accordance with my religious beliefs," Ahmad said in an affidavit.

"I was shocked that the government had thought it necessary to regulate the deeply personal religious choices of a small minority of women in Quebec."

Quebec Justice Minister Stéphanie Vallée, seen here with cabinet director Nathalie Roberge, right, says the law is necessary for communication, identification and security reasons. (Jacques Boissinot/Canadian Press)

Ihsaan Gardee, executive director of the National Council of Canadian Muslims, said at the news conference the law was another example of politicians targeting the Muslim community for "electoral gain." The next provincial election is slated for October 2018.

Quebec Justice Minister Stéphanie Vallée maintains the law is needed for communication, identification or security reasons.

The law, Vallée argued, represents a "well-balanced response" to a debate over the reasonable accommodation of minorities that has been ongoing in the province for the past 10 years.

Last month, in the face of mounting criticism and confusion, she laid out guidelines for when it should be applied.

Feds 'committed to upholding rights'

On Tuesday, Vallée told reporters she was confident the law would survive a court challenge, but she didn't rule out invoking the notwithstanding clause in the Canadian Constitution.

While opinion polls suggest Quebecers were in favour of a law on religious neutrality, the practical application has been more problematic.

The ban was panned by Quebec's association of municipalities, as well as both outgoing Montreal mayor Denis Coderre and mayor-elect Valérie Plante. The premiers of Alberta and Ontario have also denounced the law.

Prime Minister Justin Trudeau has said governments shouldn't tell women what they can and cannot wear.

On Tuesday, Attorney General Jody Wilson-Raybould said the federal government is "aware that an application has been filed in Quebec and we are reviewing it carefully."

"I am committed to upholding the rights of all Canadians under the Charter of Rights and Freedoms," she said in a statement.

Ihsaan Gardee, executive director of the National Council of Canadian Muslims, accused the Quebec government of targeting Muslim women for political gain. (CBC)

Jean-François Lisée, the head of the Parti Québécois, which has pressed for an even stronger religious neutrality law, called the court challenge "extremely predictable."

​For his part, Premier Philippe Couillard maintained the law was crafted to be in compliance with both the provincial and Canadian charters. Catherine McKenzie, the lawyer for the plaintiffs, disagrees.

"We feel that there is fairly clear case law from the Supreme Court of Canada saying that those types of choices are a violation," she said.