Association of Salaried Medical Specialists executive director Sarah Dalton said increasing the cap was the "right and logical" thing to do, and strong leadership was needed to make this happen.
Given the shortage of doctors in New Zealand, a year-on-year increase was needed.
An incremental approach would mean by the time students progressed to clinical training, the system was able to accommodate them, she said.
The university confirmed last week that although it had told then minister of health Andrew Little, senior health officials, and the Tertiary Education Commission (TEC) last year it was willing to take on a further 18 students, this had not been approved for 2023.
While this would require co-ordination to ensure adequate access to clinical training, the university did not expect 18 more places — bringing the domestic admissions cap to 300 — would create a problem.
However, explanations for the decision have not been forthcoming.
The TEC said while it administered funding, Te Whatu Ora Health New Zealand (HNZ) and the Ministry of Education set the cap.
The ministry said HNZ was the appropriate agency to respond.
HNZ said decisions on the number of government-funded medical school places was made by the Cabinet, and did not say what recommendations — if any — it made on the issue.
However, interim chief people officer Jim Green said training was a significant investment, and the medical pipeline needed to produce graduates who met the needs of the health system.
A spokesman for new health minister Dr Ayesha Verrall said given future options remained under consideration, what had or had not gone to the Cabinet would not be discussed.
Dr Verrall said the decisions were made before she became health minister.
"New Zealand does need more medical professionals so I will be having discussions with involved parties," she said.
Resident Doctors’ Association national secretary Deborah Powell said there appeared to be "a whole load of buck passing" in the responses.
"We have always been informed this is a matter for Cabinet due to the costs of funding medical school placements.
"It is clear we need more. Someone simply has to make the decision to do so," she said.
National Party MP and health spokesman Dr Shane Reti said New Zealand needed to produce home-grown medical practitioners, and National would have funded the 18 medical school places.
"It is simply hard to believe that in the middle of a health workforce crisis Ayesha Verrall and the Labour Government have made no provisions for increasing medical school places."
He had pressed the issue last year in two written parliamentary questions.
The first asked former minister of education Chris Hipkins in June if any new medical school places had been funded in Budget 2022.
Mr Hipkins replied no funding had been provided specifically for this.
In August, Mr Little was asked if the Auckland or Otago universities had requested to increase their medical school intakes.
Mr Little responded these were among regular requests by tertiary institutions for more funding, and it was not possible to provide details.
