The provincial government says it's weighing different options to block the Harper government's appointment of Marc Nadon, which is already under attack.
The dispute, which is unusual in the naming of a Canadian Supreme Court justice, has already sidelined Nadon from hearing cases and left the high court short one judge.
A Toronto lawyer fighting a legal challenge against the appointment argues that Nadon does not meet the requirements to fill one of the three spots reserved for Quebec on the nation's high court.
Now the provincial government is saying it might join that case, launched by Toronto lawyer Rocco Galati, or will contest the nomination through other means.
Alexandre Cloutier, the intergovernmental affairs minister for the Parti Quebecois government, said the Marois government could join the Galati case, table a motion in the provincial legislature, or file a motion with the province's Court of Appeal.
"Multiple scenarios are currently being considered," Cloutier told a news conference Thursday.
"I can't tell you which one we'll prefer. Obviously a decision will have to be made very soon."
Galati argues that Nadon — formerly a Federal Court of Appeal judge — does not qualify for the Quebec spot. He says only judges from Quebec's appeals or superior courts, or lawyers who have belonged to the province's bar for at least 10 years, can be appointed to the Supreme Court.
The provincial minister is also raising concerns about Nadon's residential status. Cloutier cited a report that the judge lives in Ontario, and he told reporters at a news conference: "I'm inviting our journalist friends to answer this question, to find out, for how long has he been living in Ontario?"
Cloutier added: "We have a right to three judges and we'll insist on it. It's clear that we'll make sure Quebec's voice is heard in the Supreme Court."
The three Quebec seats are guaranteed under the law, in the Supreme Court Act. The statute states that at least three of the nine judges should be named from Quebec's "Court of Appeal or of the Superior Court of the Province of Quebec or from among the advocates of that Province."
An expert in maritime law, Nadon was born in Quebec and practiced at Fasken Martineau in its Montreal and London, UK, offices.
He was named to the Federal Court in 1993, and has since served on the Federal Court of Appeal, the Competition Tribunal, and the Court Martial Appeal Court of Canada.
The federal government continued to defend the appointment Thursday.
Justice Minister Peter MacKay said the government believes Quebecers on the Federal Court have a right to serve on the Supreme Court.
"The eligibility and the opinion that we have received from (ex-Supreme Court justice) Ian Binnie, which has also been endorsed by Supreme Court Justice Louise Charron, as well as a noted constitutional expert, Peter Hogg, is very clear," MacKay told the House of Commons on Thursday.
"In fact, we believe that Justice Nadon is eminently qualified. We are certain that he will serve the court and the country with distinction and will receive the clearance he needs to join his colleagues on the Supreme Court of Canada."
The opposition calls the Harper government's handling of the appointment unacceptable. The Liberals want it immediately referred for the Supreme Court's opinion, as suggested by the Quebec bar association.
"It makes no sense, for Quebec and for all of Canada, that one of our Supreme Court judges can't sit for months and maybe years to come," Liberal MP Stephane Dion told the House of Commons on Thursday.
"Canada needs all its judges at a time when the court is preoccupied with important cases."
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