A pilot scheme is being carried out in Auckland to decide whether a new kind of health worker could take on duties so surgeons are free to perform more non-urgent operations.
Physician assistants, mostly former nurses, are used widely in the United States.
A pilot involving two physician assistants from the US will begin at the Counties Manukau District Health Board in July.
They're to be supervised by senior doctors, with duties such as physical examinations, collecting samples, ordering simple tests and developing treatment plans.
Junior doctors say that's their job, and they oppose the initiative.
Resident Doctors Association general secretary Deborah Powell, says employing physician assistants will undermine junior doctors' training.
"As we understand it, they'll be assessing patients, ordering investigations, working them up to go into theatre, then assisting in theatre and they're looking after them post-operatively, which is what registrars and house officers do as part of their training programmes."
The head of the Auckland University Medical School, Iain Martin, says there is more than enough work to go around in the health system in the next 20 or so years, and proposed new role complement rather than undermine the work of junior hospital doctors.
The Government's Health Workforce group is behind the plan, backed by four Auckland and Northland District Health Boards and the University of Auckland.