The $170,000 spent on locums to staff Porirua's after hours service each month would be better spent employing permanent doctors, the junior doctors' union says.
Currently, the clinic at Kenepuru Hospital is staffed overnight by locum GPs, but Health New Zealand has proposed replacing doctors with a helpline.
Resident Doctors' Association national secretary Dr Deborah Powell said the union would be "happy to help".
"It does seem bonkers to us that we can't sit down with Te Whatu Ora and find a sustainable alternative, a cheaper option for staffing that ED, so the people of Porirua can have some security."
The money being spent on locums could be used to employ six house officers and six registrars, she said.
"Working in Kenepuru Hospital's ED could be a great training experience for doctors training in emergency medicine, general practice, acute medicine, rural hospital medicine and paediatrics."
Kenepuru Hospital provides services to around 120,000 people who live in Porirua, Tawa and Kāpiti Coast.
"If Te Whatu Ora stops employing doctors at Kenepuru Hospital overnight, patients will just end up at Wellington Hospital, one of the most overcrowded emergency departments in the country," Powell said.
In a statement, Te Whatu Ora Capital, Coast & Hutt Valley Hospital and specialist services group director operations Jamie Duncan said the $170k figure was outsourcing costs for all shifts - not just overnight.
Duncan said the suggestion Powell made had not been presented at any of the regular meetings it has and would likely not be feasible.
"For example, the KAMC is an urgent care facility, meaning that hours that an RMO works at the KAMC would only account for hours they are required to work toward becoming an urgent care fellow - not the hours they would be required to work toward for other specialties such as emergency medicine, geriatric care, etc.
"Determining the best model to continue delivering overnight healthcare advice and support for the communities that use the KAMC is an ongoing piece of work, and we continue to work closely with our union partners to explore all options."
Duncan said they remained focused on finding solutions to staffing issues and ensuring people have access to medical care and advice overnight.