Prime Minister Tony Abbott has been accused of making a "calamitous captain's call" for deciding to throw his support behind a plan to set up another Australian medical school.

Medical groups are furious the federal government will help fund the new Curtin University medical school in Perth, saying it is part of a cynical bid to shore up softening Coalition support in Western Australia.

Mr Abbott flew to Perth on Saturday ahead of an announcement about federal support early on Sunday. Fairfax Media understands Mr Abbott will pledge millions of dollars for the project.

Colin Barnett's WA government has long been in favour of the plan but consecutive federal health ministers have been cool on it.

The Australian Medical Association says Mr Abbott made another "captain's call" to support the plan, possibly overruling​ Health Minister Sussan Ley.

"It's a calamitous captain's call by Captain Chaos. That's the only way to describe it because it's going to cause chaos with the medical training of students," medical association President Brian Owler said.

Professor Owler​ said Ms Ley sought his advice on the plan and he – along with a number of other medical groups – was adamant it was a bad idea.

The Australian Medical Association believes the country already has too many medical schools pumping out graduates who cannot find internships or specialist training places. Australia has gone from 10 to 18 medical schools in the past decade.

Professor Owler believes the decision was made to give Mr Abbott something to announce to help the Coalition's falling stocks in WA.

"I don't know that there's any other way to interpret it," he said. "Politics has taken precedence over good policy."

James Lawler, president of the Australian Medical Students' Association, says his organisation sought Ms Ley's views on the proposal about a month ago.

"She told us that she didn't believe we needed a new medical school and there wouldn't be funding for that in the budget. But all of a sudden Tony Abbott's flying to WA to announce it," he said.

However, a spokesman for Ms Ley – who will not be in Perth for the announcement – said the minister had consulted with a number of stakeholders on the plan, not just medical groups.

"She supports it," the spokesman said.

Another government source said Ms Ley actually urged Mr Abbott to get behind the proposal.

Labor's health spokeswoman Catherine King said the location of any medical school was a matter for the government.

"But unless it's matched by ongoing funding for training and placement, it's pointless as students who graduate, without being offered a placement or training, won't be able to qualify and will simply move back east," she said.

Mr Abbott's office declined to comment.

The Prime Minister has been criticised for making "captain's calls" in the past, most notably over his decision to knight Prince Philip and his proposal for a generous paid parental leave scheme, which he has since abandoned.

Tony Abbott branded 'Captain Chaos' over medical school plan