Open this photo in gallery:

EMS prepare their ambulances at the University of Alberta Hospital in Edmonton.JASON FRANSON/The Globe and Mail

Four former deans of medicine in Alberta have joined a growing chorus of critics asking Ottawa to intervene in the province’s dual-practice health care model, which allows eligible doctors to toggle between the public and private systems.

Tom Feasby, Jon Meddings and Eldon Smith, all formerly with the University of Calgary, and Tom Marrie, who was with the University of Alberta – sent a letter on the contentious issue to Prime Minister Mark Carney on Tuesday. They expressed “deep concern” about the public-private model and assert it violates the Canada Health Act.

“It is clear that the Alberta government is not going to change course and, therefore, we strongly request that you and the federal government step in and defend the principles of the Canada Health Act,” said the letter, which was also sent to Alberta Premier Danielle Smith.

Opinion: Mark Carney has said nothing about Alberta’s health care reforms. That’s a good thing

Alberta’s model is unlike any other in Canada, allowing some surgical specialists to bill the public purse while also privately charging patients for their services. The legislation, which took effect Sept. 1, covers such procedures as hip and knee replacements, cataract surgery and dermatology.

There is intense debate about whether it contravenes federal law.

The model has come under widespread scrutiny, including from the Canadian Medical Association and its Alberta counterpart, which argue it could create a two-tier system where people who can afford to pay out of pocket receive faster care. In March, 23 health and labour organizations across the country called on Mr. Carney to take action.

Dr. Meddings, in an interview on Wednesday, said there are other countries where a similar model has worked, but Alberta’s health care system is not conducive for a marriage between public and private care.

“I have nothing against dual practice per se, or some sort of private practice, in the same way as I don’t have anything against somebody paying extra money to fly business class on an airplane,” he said.

“The difference in Alberta is, because we have such a restricted number of both beds and physicians, that when somebody pays for this, it’s not an extra spot that wouldn’t have been used. It is taking it away from somebody who would have needed that spot.”

The Prime Minister has been largely silent on the issue, but federal Health Minister Marjorie Michel has expressed concern about how the policy will co-exist with the Canada Health Act.

Alexandre Bergeron, press secretary to Ms. Michel, did not address the letter directly in a statement on Wednesday but said the minister is in conversation with Adriana LaGrange, Alberta’s Minister of Hospital and Surgical Health Services.

“Minister Michel is engaged in ongoing, targeted discussions with her Alberta counterpart focused on ensuring access to medically necessary care and the core principles of the public system are protected while respecting Alberta’s jurisdiction,” he said.

Maddison McKee, press secretary to Ms. LaGrange, said in a statement that Ottawa must respect Alberta’s jurisdiction to determine how health care is delivered. She also reiterated the government position that dual practice does not contravene the Canada Health Act.

“Our priority is a strong public system and ensuring Albertans never have to pay out of pocket for medically necessary care,” Ms. McKee said. “Expanding access through dual practice does not take away from that. It adds to it. This is not an either/or debate. It is about giving Albertans more choice.”

Public-private health care model coming to Alberta breaches Canada Health Act, legal expert argues

The former deans said dual practice will harm patients by allowing those who can afford private care to jump to the front of the line, rather than providing care to the sickest first. This, they stressed in the letter, is what the Canada Health Act was designed to prevent.

Alberta has defended the dual-practice model as a way to reduce strain on the public system. The signatories argue that there is no evidence that shows a parallel public-private system will have that effect. Rather, they said, it will cause patients to wait longer in the public stream.

The province has said 400 expressions of interest were received over the summer to join the dual-practice system. As of mid-September, physicians were able to formally apply. Surgeries are expected to begin later this fall when the application process is complete.

While the letter did not specify what Ottawa should do, Dr. Meddings sees two ways in which the federal government could address the Alberta practice.

He said Mr. Carney and Ms. Michel can use the power of “moral suasion” with their counterparts in Alberta to push for changes to the legislation.

There is also what Dr. Meddings described as the “nuclear option,” where the federal government withholds or deducts health transfer payments to Alberta, which is permitted if a province violates the Canada Health Act.