A major international legal organization says Prime Minister Stephen Harper owes Canada’s Chief Justice Beverley McLachlin an apology.

An unprecedented spat broke out between the Prime Minister’s Office and the country’s top court in May after the Prime Minister's Office accused McLachlin of acting “inappropriately,” during the failed nomination of Justice Marc Nadon to the Supreme Court.

Now, the International Commission of Jurists (ICJ) says the PMO and Minister of Justice Peter MacKay were “unfairly conflating the issue.”

Accusations of 'lobbying'

At the time, nameless government sources were quoted in published reports accusing McLachlin of having “lobbied” the government against Nadon’s appointment in the summer of 2013.

The Supreme Court would go on to eventually hear a reference on Nadon’s appointment in January and declared him ineligible to join the High Court in March.

It is difficult to see why there was a need to air them in the court of public opinion several months after the fact. - Wilder Tayler, secretary general, International Commission of Jurists

After the allegations of lobbying emerged, the Supreme Court, in an unusual move, issued a public statement denying the allegation and clarifying McLachlin only ever raised a question about Nadon’s eligibility to sit on the court before he was nominated, and long before the issue actually ended up before the Supreme Court.

The court pointed out the chief justice routinely discusses such matters with the government and there was nothing unusual about this particular time.

'Encroachment upon the independence'

ICJ secretary general Wilder Tayler said “the criticism [of McLachlin] was not well-founded and amounted to an encroachment upon the independence of the judiciary and integrity of the chief justice.”

ICJ was asked by a group of Canadian lawyers and academics to comment on the issue because they were concerned the independence of the Supreme Court was under attack.

The Geneva-based organization says it contacted the Prime Minister’s Office to get its side of the story, but has not received a response.

After a review of the facts as presented by the letter of concern, the ICJ concluded: “The prime minister and minister of justice could best remedy their encroachment upon the independence and integrity of the judiciary by publicly withdrawing or apologize for their public criticism of the chief justice.”

“If the concerns were not of a character to warrant formal complaint,” Tayler adds, “it is difficult to see why there was a need to air them in the court of public opinion several months after the fact.”

The Prime Minister’s Office says it has nothing to say about the matter except, “We have seen the letter. We have noted it.”