A Quebec historian has launched a formal complaint against the chief justice of the province's Court of Appeal over comments she made about the province's religious symbols law.

Frédéric Bastien, who teaches history at Dawson College, said taken together, Justice Nicole Duval Hesler's comments and actions show she has a political bias against Bill 21.

He revealed via Facebook that he has filed a complaint with Canada's judicial council, the body responsible for disciplining federally appointed judges.

"A judge should not enter the political fray. She should speak when she renders a judgment, and in between judgments she should be as discrete as possible," he said in an interview.

Two civil rights groups were in court last week trying to have the law suspended while it is being challenged in court. Bill 21 bans some civil servants, including teachers, government lawyers and police officers, from wearing religious symbols.

During the hearing, Duval Hesler declared herself a feminist when she should have kept her personal ideologies to herself, Bastien said. She also said the law specifically targets Muslim women who wear hijabs, while the text itself does not mention Muslim women specifically, he said.

She associated Bill 21 with people who had a "visual allergy" to religious symbols, likening support of the law to a disease, he said.

In addition, she has, outside the courtroom, spoken in favour of multiculturalism and religious accommodation, Bastien said.

Nicole Duval Hesler is the chief justice of Quebec. (Court of Appeal of Quebec)

Event also problematic, Bastien says

He also has a problem with the fact that Duval Hesler is speaking at an event next week hosted by the Lord Reading Law Society.

The law society opposes Bill 21, and so her presence is a political statement, he said.

This summer, Bastien expressed interest in running for the leadership of the Parti Québécois, which supports the law — interim Leader Pascal Bérubé has said it does not go far enough.

The complaint, he said, is not politically motivated and is in line with positions he has held in the past.

Bastien said Duval Hesler should recuse herself from the case. If she doesn't, he says Sonia LeBel, the provincial justice minister, should ask her to.

A spokesperson for LeBel declined to comment. Duval Hesler also declined to comment, through her assistant.

Premier François Legault wouldn't comment about the complaint, but did point out that the hearing in question is only about temporarily suspending the law, not about the content of the law.

He said the government is confident the suspension of the law will be avoided.

Judge's views can't be assumed, expert says

Robert Leckey, dean of the faculty of law at McGill University and a critic of Bill 21, said in an interview it is "striking" that a judge's inclination to favour fundamental rights and the Charter of Rights and Freedoms is seen as bias.

He said as a judge takes in information, they start to form their tentative views, and may give the courtroom a sense of what they are thinking. That is a normal process — "none of that indicates inappropriate bias or partiality."

"Judges say things all the time during a hearing. They ask questions, they play the devil's advocate. It's dangerous to kind of assume you know what a judges' personal views are based on questions they ask."

He said Duval Hesler's comments will be examined by a group of judges and lawyers, and remarked at how the concerns about her impartiality are now playing out online and in the media.

"It's a reminder of how politicized things are around the challenge to Bill 21," he said.