OTTAWA - Stephen Harper's latest picks for Canada's top court show little sign he's trying to stack the bench with ideological soul mates, court watchers and opposition parties say.

The prime minister nominated Monday two Ontario judges — Justice Andromache Karakatsanis and Justice Michael J. Moldaver — to fill vacancies at the Supreme Court of Canada.

They were among six judges unanimously recommended by a parliamentary review committee, which included Liberal MP and former justice minister Irwin Cotler, New Democrat MP Joe Comartin and three Tories.

Despite that unanimity, both opposition parties raised concerns that Moldaver is not bilingual — a fact interim NDP Leader Nycole Turmel termed "very regrettable."

Karakatsanis speaks three languages: French, English and Greek.

Apart from the language issue, however, neither New Democrats nor Liberals questioned the political leanings or legal qualifications of the pair to sit on the bench of the highest court in the land.

"I've worked with both of them in different ways and they're both very intelligent, highly, highly qualified people," said interim Liberal Leader Bob Rae.

The nominees are to appear before a Commons committee Wednesday to answer MPs' questions. But, even with opposition concerns about Moldaver's lack of French, the hearing is essentially a formality.

The committee does not have the power to block an appointment. And Rae called on MPs not to politicize Wednesday's hearing, to treat the nominees "with a degree of respect and understanding" — unlike the vicious partisan battles that have broken out in the United States over judicial appointments.

Critics have long predicted that Harper, once he secured a majority, would try to tilt the ideological balance of the nine-member court to better reflect the Conservative government's disdain for judicial activism and its tough-on-crime agenda.

But, for the most part, the two new nominees were deemed to have an essentially neutral impact on the court's balance.

They will fill the voids left by the retirements of Ian Binnie and Louise Charron.

The appointment of Karakatsanis retains the gender balance of the court at four female to five male judges. The 56-year-old is a relative newcomer to the bench, having been appointed to the Ontario Superior Court in 2002 and promoted to the Ontario Court of Appeal in 2010.

Prior to that, she was a senior provincial bureaucrat. She served as the top civil servant to the Ontario Harris government, which entailed working closely with cabinet ministers, several of whom now play senior roles in Harper's ministry: Finance Minister Jim Flaherty, Foreign Affairs Minister John Baird and Treasury Board President Tony Clement.

Despite those Conservative connections, Cotler noted that Karakatsanis was first appointed to the bench by a federal Liberal government. A Liberal government also promoted Moldaver to the province's appeal court.

"I don't think these appointments, in that sense, can be said to be politically or ideologically motivated," Cotler said in an interview.

"I think they're both merit-based choices."

Moldaver, 63, has been an outspoken critic of the way in which the Charter of Rights has been used frivolously by some lawyers to drag out trials, milking their wealthy clients or the legal aid system.

Queens University law professor Don Stuart said Moldaver's speeches and recent judgments suggest he's "a charter skeptic," which he said would be consistent with the Harper government's philosophy.

"Occasionally he's written judgments which are pro-accused but, more recently, he seems to have been rather conservative, to say the least, on charter rights. So in that sense, it might be an ideological choice," Stuart said in an interview.

That view was echoed by the Criminal Lawyers Association. Association president Paul Burstein said Moldaver "exhibited a courageous defence of civil liberties" in his early rulings but "has since developed a more distinct ideology."

"Hopefully, we will now see a return to his earlier way of thinking about criminal justice and the charter," Burstein added.

Moldaver himself has argued he's not a "charter basher" and the NDP's Comartin said he thinks the judge has gotten an unfair rap based on one controversial speech in 2006.

If one looks at all Moldaver's rulings and speeches, Comartin said: "He very much is in the middle of the road."

Karakatsanis has made fewer rulings on charter issues so she's harder to read. Burstein said she's "somewhat of an unknown quantity when it comes to civil liberties and criminal justice."

"The one significant charter decision which she recently authored, concerning the right to privacy in our computers, reflects a healthy respect for the rights of privacy but tempered by an unfortunate compromise on the judicial enforcement of that right," Burstein said.

However, Stuart said his reading of Karakatsanis's rulings suggests "if anything, she tilts to the accused."

Overall, Stuart said the two new nominees aren't likely to change the ideological balance on the court. Karakatsanis seems likely to fill the role played by Binnie, who tended to favour the rights of the accused, while Moldaver is likely to fill the role played by Charron, who tended to favour the state.

Comartin, the NDP's representative on the parliamentary review panel, said the confidentiality of the process prevents him from explaining why he joined in unanimously recommending the unilingual Moldaver as one of the six finalists.

The NDP supports requiring all Supreme Court judges to be fluently bilingual, a position Comartin and Turmel reiterated Monday.

He urged reporters to ask Harper why he chose a unilingual judge.

Called to the Ontario bar in 1973, Moldaver was appointed to the province's supreme court in 1990 and to its appeals court in 1995. He lectured at the University of Toronto law school from 1978 to 1995.

He and Karakatsanis were part of a pool of 12 candidates forwarded by the justice minister to a selection panel of five members of Parliament.

The panel then gave an unranked list of six unanimously approved candidates to the prime minister and justice minister.