Health spending needs a boost of $1.1 billion from this week's Budget to keep up with rising costs and a growing, and ageing population, say unions and senior doctors.
An analysis by the Council of Trade Unions and the Association of Salaried Medical Specialists found an extra $721 million was needed just to maintain existing health services.
It said the government had already committed $375m in new costs for the coming year, and these needed to be added to the budget increase, bringing the total to $1.1bn.
Association of Salaried Medical Specialists executive director Ian Powell said he was far from optimistic that health spending would receive the top-up it needed.
"Because at the end of the day, although it is health professionals and other health workers who carry the burden of this political neglect from government, it is patients who are the biggest losers."
The National-led government will deliver its ninth Budget on Thursday.