OTTAWA - Two Supreme Court justices have announced they will retire this summer, allowing Prime Minister Stephen Harper to begin reshaping the country's highest court.

Justice Louise Charron will retire on Aug. 30 and Justice Ian Binnie says he will leave the same day, or later if there's a delay in appointing his successor.

Chief Justice Beverley McLachlin says the departures will leave an important void at the court.

"Both have served the Court with great wisdom and dedication and have made significant and lasting contributions to the administration of justice in Canada," she said in a statement.

"They are valued colleagues and friends. We will miss them."

With several justices nearing retirement, it was expected that it would fall to Harper to appoint replacements, but it was thought he'd have more time.

Binnie, 72, has been at the Supreme Court since 1998 and was due to retire within the next three years.

"Much as I will miss the work and my colleagues, I am now well into my fourteenth year on the Court and the time has come to return to Toronto to pick up some of the threads of an earlier existence," Binnie said in a statement.

Charron joined the bench in 2004, but at age 60 is stepping down well before the mandatory age of 75.

"My husband and I both enjoy good health. We have a great family and wonderful friends," she said in a statement.

"I have been a judge for 23 years now and the seventh anniversary of my appointment to the Court, August 30 next, seems like the perfect time to move on."

McLachlin said she is certain the government will make the selection of new justices a priority "with all the care and deliberation that is required in the circumstances."

Harper has already appointed two justices to the bench in the last five years.

In a news release issued late Friday, the Prime Minister's Office said filling the latest vacancies will be a priority for his government.

A list of qualified candidates will be compiled and reviewed by a selection panel of three government and two opposition MPs. The panel will provide a short list of six candidates to the Prime Minister and justice minister, the release said.

The two selected nominees will then appear before a parliamentary committee to answer questions from MPs.

During the election campaign in April, Harper laid out some of his vision for how he'll select the nominees.

"We will pick people, as we've done in the past, people we think are strong independent legal minds," Harper said at the time.

Binnie and Charron were both from Ontario, meaning a lot of lawyers in the province are likely dusting off their resumes, said Philip Slayton, a lawyer and author of a new book about the power of the court.

It would make sense for Harper to fill the vacancies before the start of the court's fall session, Slayton said, although there is no deadline.

The Judges Act provides that a judge of the Supreme Court of Canada may, for a period of six months following his or her retirement, continue to participate in judgments with respect to cases heard prior to retiring.

These two vacancies, plus at least another three which could come within the next four years means the court is likely to change a great deal over the Harper government's mandate, he said.

"This court will become completely a Harper court," Slayton said.

"You can presume that Prime Minister Harper will not appoint judges that he doesn't think of as broadly in line with his point of view and his general political ideology."

For example, Slayton said, it's likely that Harper would appoint someone who favours the power of police.

Both of Harper's past appointments -- Thomas Cromwell and Marshall Rothstein -- were seen as being justices who were right of centre, Slayton said.

But he also noted that Rothstein's name was one that had surfaced during Paul Martin's term as prime minister via a selection committee.

Rothstein also appeared before a parliamentary committee before taking his spot on the bench.

Harper bypassed both committees in selecting Cromwell.

There is no requirement that Supreme Court justices must have served in other courts, only that they be a member of the bar for at least 10 years.

"But it's very important that we don't just pick up the newspaper one morning and find out who these new judges are," Slayton said.

"We need a transparent process over a period of time that gives everybody a chance to look at who is proposed."