Doctors fear some cancer patients will face life-threatening delays if a serious shortage of senior doctors is not fixed.

The Regional Cancer Treatment Service, which cares for patients in and around Manawatū, Taranaki, Hawke's Bay, Whanganui and Wairarapa, has not been allowed to recruit the number it needs.

That is despite Te Whatu Ora saying its current hiring restrictions do not apply to medical roles.

There are huge risks for the cancer service if the short staffing is not addressed, says Palmerston North medical oncologist Richard Issacs.

"If you've got a service that cannot accommodate all the people who need that, there will be waiting times. And if you wait longer for treatment, your risk of dying increases."

An internal Te Whatu Ora/Health NZ report delivered 18 months ago recommended hiring four more senior doctors, one of them part time, to be able to meet demand for cancer treatment.

They would be added to the existing staff - which Te Whatu Ora says is the equivalent of nearly nine full-time roles.

None have been hired.

Sarah Dalton, the executive director of the the senior doctors' union the Association of Salaried Medical Specialists, says the extra roles were added to last year's budget but were then crossed out.

Instead, one position has been approved but has not been filled.

Doctors and other medical staff there are very upset, she says.

"They are a significant service on the brink of collapse."

Issacs, a member of the union, has been at Palmerston North Hospital since 1996.

He and his colleagues are doing work in their own time and already struggle to keep seeing patients if any doctors are sick, he says.

"We just don't have the capacity to manage all the clinics we need to do when those things happen unexpectedly. We have no flexibility in the system.

"Everybody has to do extra to try and cope. It's non-sustainable."

If the service can no longer keep up with the needs of patients, people will with have to wait for a possibly dangerously long time or have to go to other centres, such as Wellington, he says.

He doens't understand the assertion from Te Whatu Ora head office that any clinical staff needed in hospitals are being hired, despite recruitment restrictions to try to stay to budget.

"We need staff to be able to maintain a high quality service and they need to jolly well support us doing that, particularly when they've been behind an investigation that defined how many people we needed," he says.

"So I utterly don't accept a reluctance to try and man our service adequately."

Dalton says the only reason patients are still being treated on time is because doctors are often putting work ahead of themselves or their families.

They risked burning out, which will make the problem worse, she says.

In a statement, Te Whatu Ora Mid Central operations director Sarah Fenwick says the increased staffing recommendation had been sent to for regional and national approval in March 2023.

It was now in its draft budget for 2024/25.

She says, in the meantime, there's in an interim plan in place to keep caring for patients and there are no plans to delay treatment.

-RNZ.