Wagner's appointment Tuesday filled the seat left empty when Justice Marie Deschamps retired in August. It reduced to three the number of women on the nine-member court.
NDP justice critic Francoise Boivin called Wagner's "a great nomination" in part because it filled a void in commercial law expertise created by Deschamps' departure. But Boivin was disappointed that a woman was not tapped to replace Deschamps.
"I'm very concerned with the fact we're not replacing Justice Deschamps by a woman justice," Boivin told The Canadian Press Tuesday.
Boivin was on a panel of MPs that recommended three choices to Prime Minister Stephen Harper. Wagner was one of them, she said, but she declined to say if at least one woman was on the short list.
Boivin said the government should be on notice to correct the gender imbalance over the next two years, when two male justices from Quebec reach the mandatory retirement age of 75.
"Let's just not forget the gender balance of the Supreme Court," said Boivin.
"It is as essential in a sense, as having three seats for Quebec."
Queen's University law professor Kathleen Lahey blasted the government for not appointing another woman.
"Going back to a 33-per-cent minority for women is something that will seem out of date to many Canadians," Lahey said in an interview.
"This is the 21st century, and this is really a rather 20th century version of a top court."
Sebastien Grammond, the dean of civil law at the University of Ottawa, said the Harper government will have two more chances to appoint a woman when Quebec justices Morris Fish and Louis LeBel retire in 2013 and 2014 respectively.
"It may very well be they will appoint a woman next time," Grammond said in an interview. "They would be replacing a man with a woman.
"As long as it evens out in the long term, I think it's OK."
Grammond said Wagner brings strong skills in commercial law, honed by years as a senior litigator. His subsequent appointment as a judge broadened his expertise in criminal law.
Wagner became a lawyer in 1980 and worked in civil and commercial law before being named to the Quebec Superior Court in 2004. He was raised to the appeal court in 2011.
It was the Liberal government of Paul Martin that first appointed him to the bench eight years ago.
Wagner became Harper's fifth Supreme Court appointment, which means he has now appointed a majority of the country's high court.
"What's interesting is he (Wagner) crosses party lines in a way," said Grammond.
But he added: "I think we tend to make too much of this. It's not the U.S. Supreme Court where judges vote typically along party lines. It's quite different in the Supreme Court of Canada."
Wagner is also known as a good communicator — a trait that is sometimes seen as noticeably lacking in court judgments at any level.
"He's going to be a great asset," said Boivin.
"When he writes, you understand what he writes. He's known for writing in ways that are easy to understand, not too long decisions and so on."
Harper said Wagner was selected after a rigorous evaluation.
"Held in high esteem by his judicial colleagues and members of his bar association, he is an exceptional candidate with the skills and qualifications needed to serve Canadians well," Harper said in a statement.
The new justice was chosen from a pool of candidates picked in consultation with the attorney general of Quebec and senior members of the judiciary as well as prominent legal organizations. Members of the public were also invited to submit their suggestions for qualified candidates.
The nominee will be questioned by a select parliamentary committee on Thursday.
Wagner also comes from a family prominent in Quebec legal and political circles.
His father, Claude Wagner, was a Crown attorney, a law professor, a judge and a senior politician in the province. He served as a judge, then as solicitor general, attorney general and justice minister in Jean Lesage's Liberal government of the 1960s before returning to the bench.
The senior Wagner was elected a federal Tory MP in 1972 and ran unsuccessfully for the Conservative leadership in 1976, losing to Joe Clark.
He was named to the Senate in 1978 by Pierre Trudeau, but died of cancer the next year.
The younger Wagner earned a B.A. and a license in law from the University of Ottawa before entering practice.
Also on HuffPost