Acting Prime Minister Winston Peters says the Government "haven't got the money" to make a new pay offer to nurses who will go on strike this Thursday.
"We haven't been joking when we told the nurses via the media that this is our best offer," Mr Peters said in a news conference on Tuesday morning.
"It's not that we're not willing to - we haven't got the money."
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The July 12 nurses' strike was given the green light after members of the New Zealand Nurses organisation (NZNO) voted to reject the latest pay offer from district health boards (DHBs).
Mr Peters said the pay offer was the highest "by far" in the last 14 years.
"The Government doubled the offer from its opening position in addition to a pay increase," he explained.
"The offer sought to addressing staffing issues by adding 500 extra nurses, recognise the experience of longer serving nurses by adding to extra steps to their pay scale, and by bringing forward pay equity discussions."
He said the strike is "a sad reflection of years of underfunding and neglect by the previous government".
Mr Peters also had this message for nurses: "You could face the other consequence - that is, the previous government you had - and nothing."
He said the Government is hoping for reconciliation before the strike takes place, but all preparations have been made by DHBs to ensure the least amount of disruption to patients.
But the Opposition says the Government has "completely lost control".
"The Government must regain control of the situation and settle with the nurses as soon as possible to minimise the impact of this strike on patients and the sector," National's health spokesperson Michael Woodhouse said.
Hundreds of surgeries and appointments that haven't already been moved will be shifted to prepare for the 24-hour strike.
The NZ Nurses Organisation (NZNO) says up to 30,000 members could strike. It will be the first nurses' strike in nearly 30 years.
The first strike planned for 5 July was called off after the DHBs made a revised offer.
"Life preserving services and contingency plans are coming to completion with the twenty district health boards. We are confident that these will be in place as patient safety and public safety is paramount," NZNO Industrial Services Manager Cee Payne said.
"The issues faced and reported by our members have arisen from a decade of severe underfunding of our public hospitals which have failed to keep pace with growing community need, the ageing population and workforce, and increased costs," Ms Payne said.
DHBs are still seeking to avoid strike action, and have asked the Employment Relations Authority to help to find a way forward.
DHB spokesperson Helen Mason said, "We respect nurses right to strike in support of their claims. We also need to recognise that negotiation involves a significant degree of compromise. We have moved significantly over the last six months and have made an excellent offer."
She says hospitals across the country have already experienced "significant disruption" at a busy time of year as a result of deferring services for both planned strikes.