As Canada's chief justice sounds fresh alarms over the "serious consequences" judicial vacancies are having on this country's justice system, Prime Minister Justin Trudeau says the federal government is working on appointing "quality" judges.

In a session wrap-up press conference on Tuesday, Supreme Court top judge Richard Wagner was highly critical of the current pace of judicial appointments, warning that languishing vacancies on courts across Canada are exacerbating "an already alarming situation."

"These empty positions have a significant impact on the administration of justice, the functioning of our courts, and access to justice for the public," Wagner said. "It has major effects in every province of this country."

There are currently 79 federal judicial vacancies, according to the office of the Commissioner for Federal Judicial Affairs.

"There are candidates available in every province, so there's no reason why those [vacancies] cannot be filled," Wagner said, noting some courts have been operating for years with vacancy rates of 10 to 15 per cent.

He said it's not unusual to see some positions remain vacant for months, or in some cases, years. This, even though in most cases when judges retire they give six months' advanced notice.

Recently, following discussion at the Canadian Judicial Council, Wagner took the rare step of writing to Trudeau directly to make him aware of his concerns.

Pointing to Alberta as one example, Wagner said that nearly two dozen serious violent active criminal cases are waiting more than the 30-month period under which, since the 2016 R v. Jordan ruling, courts are to proceed to trial.

"You know what that means? That means a potential stay of proceedings in criminal matters, because there's no judges available," Wagner said, adding that provincial governments also have a responsibility to adequately fund their respective justice systems to help see these cases brought before the courts in a timely manner.

Wagner said Trudeau did call him to discuss his letter briefly, and indicated his government would "provide the best effort to appoint the best candidates" to try to address the situation.

Asked what he thinks is behind the backlog, Wagner said he doesn't know "what the problem is."

"But one thing's for sure, it's a big, big, big concern. And now, the prime minister is aware of that, and I'm confident that he will take the steps necessary to make sure that the solutions be provided."

Responding to Wagner's comments on his way in to question period on Tuesday, Trudeau seemed to echo the same pledge he made on his call with the chief justice, telling reporters in French that his government is taking the responsibility very seriously "to have quality judges across the country."

"We'll keep selecting people to serve in our courts across the country who are high quality," Trudeau said.

Facing another vacancy—this time unplanned and at Canada's top court due to justice Russell Brown's snap resignation amid a misconduct probe on Monday—Justice Minister David Lametti said he's working "diligently" to clear the backlog, but in the case of Brown's replacement, he could not provide a timeline.

Lametti leads the federal government's work recommending appointments for judges to Canada's federal, appeal, superior and supreme courts.

"In all appointments to the bench, we search for quality and we search for diversity… We're looking for the best candidate, the person who brings a great deal of intellectual capacity to the court, and we’re also trying to promote diversity. The bench has to look like the rest of Canada."

According to the federal government, since the Liberals came to power in 2015, more than 620 judges have been appointed.

"Of these judges, more than half are women, and appointments reflect an increased representation of visible minorities, Indigenous, 2SLGBTQI+, and those who self-identify as having a disability," reads the latest release announcing new judicial appointments on June 12.