Nurses, midwives and health care assistants at 20 District Health Boards (DHBs) have rejected a proposed collective agreement.
The New Zealand Nurses Organisation (NZNO) said 26,000 members had voted not to accept the DHBs' proposed multi-employer agreement during the current contract negotiations.
Industrial advisor Lesley Harry said the union would be negotiating with the DHBs again on Thursday and hoped they would reconsider the offer