Senior doctor groups say a proposal to let patients in public hospitals pay for extra treatment will lead to a two-tier health system.
But Dunedin Hospital clinician Chris Jackson, who came up with the idea, says it will boost the public system because patients won't need to go back and forth between public and private specialists.
The Otago and Southland district health boards are calling for public submissions on a document called Bridging the Gap, which outlines ways for patients to pay for treatments that are not publicly funded.
Dr Jackson, a cancer specialist, says that dividing care between public and private providers is stressful and expensive for patients.
"Patients should be able to have all of their treatment under one roof," he says, "and they should just be able to top up their treatment."
Dr Jackson says patients who can't afford to pay would not be affected, because fee-payers would not be allowed to jump the queue.
Doctors would be put in 'repugnant' position
But the Medical Association and the Association of Salaried Medical Specialists (ASMS) believe that that is exactly what would happen.
They say that the proposal would put extra pressure on the public system, which is already struggling to provide the services for which it is funded, create serious inequalities and put doctors in a repugnant position.
Angela Belich, of the ASMS, says a doctor might have two patients in equal need but be able to offer only one of them a particular treatment or drug.
The New Zealand Nurses Organisation says there should be a greater level of public funding for health services instead of making patients pay.
Labour Party health spokesperson Ruth Dyson says that what is being proposed is "people being able to access public health services on the basis of money rather than on the basis of physical need, and that is not something that should be acceptable in New Zealand."
Health Minister Tony Ryall says that there are no plans for such a system to be introduced nationwide but that he is watching developments with interest.
Submissions on the document close on 2 February.