Nurses have decided to walk off the job next month.

Nurses, midwives and healthcare assistants covered by the Nursing Organisation's collective agreement have issued a strike notice for 24 hours starting 7am, on July 5.

Notice for a second, 24-hour strike from 7am on July 12 is expected next week.

DHB spokesperson Helen Mason says DHBs will do everything they can to settle the agreement and avoid the strikes.

She says they'll be in mediation with the Nurses Organisation on Friday - in the meantime DHBs will start working on contingency plans.

On Monday, NZNO members voted to reject the DHBs' revised pay offer of 9 per cent for all member nurses by August 2019.

Deputy Prime Minister Winston Peters said the Government had not given up.

"We hope they can see the wisdom of this deal in our first Budget."

He said the pay offer was the biggest in 14 years and far greater than the previous advances given from the National party.

"We've made it very clear that we understand their situation, there are other ways they can cut the deal of the $500 million plus the extra 500 nurses."

Peters said of course he was disappointed but the Government was trying to pick up the years of neglect and underfunding and was not possible in one Budget.

"There are provisions in place to ensure public safety if it does come to that but we hope it doesn't still."

Health Minister David Clark said although the announcement was not unexpected it was still disappointing.

"The Government has done all it can to avoid this strike by doubling the offer to half a billion dollars, including providing for 500 extra nurses to deal with shortages.

"We understand nurses' frustration after nine years of neglect under the previous Government but had hoped our offer, the best offered to nurses in 14 years, would be seen as the good start it represents to fixing those issues.

"I still hope that a settlement can be achieved before the strike takes place," Clark said.

So what will this mean for patients?

A Auckland DHB spokeswoman said they couldn't specify how many operations and consultations would be deferred as a result of the strikes at this stage.

Auckland DHB chief executive Ailsa Claire said the hospital will be able to maintain only essential services during the strike and many outpatient clinics will be close.

"We will still provide services defined as life preserving, and this includes some essential outpatient services such as cancer treatments.

"We ask that patients come to their scheduled appointment unless we have contacted them directly to say their appointment is being rescheduled," Claire said.

During the strike period, if you need hospital care or have an emergency, please don't hesitate to come to Auckland City Hospital or Starship Hospital or to call 111.