The next nurses strike could be for 24 hours at the end of next month, if nurses agree to it in a vote.
About 30,000 members of the union, the Nurses' Organisation, walked off the job for eight hours three weeks ago, marching in huge protests around the country.
They were back in negotiations with district health boards over a pay offer they say is not good enough, especially when many nurses are stretched thin every day.
They had until next week to vote on whether to stop work three more times: 29-30 July for 24 hours, 19 August for eight hours, and 9-10 September, for 24 hours.
District health boards said they were disappointed the nurses were voting on the matter while negotitions were still under way.
Wairarapa DHB chief executive Dale Oliff said they had worked hard to meet the union in the middle, agreeing to more than half their 63 demands.
But the union said the DHBs had not yet addressed the core problem of paying nurses what they were worth.
There are two mediation sessions this week, with the outcome of the nurses vote expected next week.