Nurses are considering a late pay offer by district health boards (DHBs) attempting to avoid a massive nationwide strike.
And they have also refused a formal request by the Waikato District Health Board to commit to calling off the strike there.
About 30,000 members of the Nurses Organisation are set to stop work on 9 June after an earlier offer they said was a 1.4 percent pay rise.
But the union's industrial organiser, Glenda Alexander, said the ballot on a new offer from the DHBs went out yesterday and nurses have until next Monday to make a decision.
There was always hope there was a way around the strike but, in the meantime, the plans remained in place, she said.
"At the moment there is a pretty stressed workforce out there that is pretty angry about how they feel they've been treated so we'll just have to wait for the outcome of our ballot," she said.
Waikato DHB asked last week for the nurses to make an exception and to call off the strike there as it grappled with the fallout from its crippling cyber outage, she said.
But Waikato nurses felt strongly they wanted to be part of any nationwide strike action, Alexander said.
"Striking is never something nurses take a decision on lightly and so it's probably significant of their real concerns about how they're feeling working in health at the moment that they want to continue with this in the circumstance," she said.
There was already an extensive plan in place to make sure life preserving services would be staffed during a strike, and that there would be enough nurses in an emergency, she said.
That could be tweaked closer to strike day, if necessary, she said.