Nurses have voted to reject the latest pay offer from New Zealand's District Health Boards (DHBs).
The NZ Nurses Organisation (NZNO) says urgent mediation is required to avoid strike action.
Industrial services manager Cee Payne says a staffing "crisis" has taken a heavy toll on nurses.
"Nurses and midwives do not trust that their work environment or patient care will improve in the short term. While the revised offer included new funding to address short staffing, concern remains that this may not be enough to make a real difference."
Nurses rejected an offer of a 9 percent pay increase over 15 months, and a $2000 one-off lump sum. Salary limits would increase for registered nurses with more than five years' experience, meaning some could get increases of about 16 percent.
Health Minister David Clark is disappointed nurses rejected the offer.
"The deal that's been rejected today is the largest nurses and midwives have been offered since their historic pay jolt 14 years ago under the last Labour-led government," he said.
"The Government has to balance pay demands across the public sector. We have gone as far as we can in terms of extra Government money, but hopefully the offer can be reconfigured in a way nurses are happy with."
The union says while the latest offer was a substantial improvement on pay, variability over pay increases has created uncertainty.
Nurses have been negotiating a pay increase for a year now. They say their pay has not kept up with other professions like police and teachers.
The union says preparations have begun for providing life preserving services in the event of a strike.
The DHBs said they are likely to recieve notice of strike action on 20 June.
Listen to both interviews in full above.