The union representing nurses has said no to an offer that would have given its members a 2 percent pay increase each of the next three years.

The New Zealand Nurses Organisation, who represent more than 27,000 nurses, midwives and health care workers nationwide, rejected an offer on Wednesday for pay through to July 2020.

Mediation between the NZNO and the country's DHBs is the likely next step towards an agreed collective agreement, NZNO industrial adviser Lesley Harry said.

"The members' rejection of the DHB offer reflected their view that the remuneration on the table failed to respect nurses, midwives and healthcare assistants and the huge effort and value they bring to patients and our communities," she said.

"The negotiating team is confident it now has a good steer from members but will also be seeking additional feedback on the areas of the offer that need to change.

"Of course, nurses and DHB employers will be doing their best to reach an employment agreement acceptable to both parties."

Any agreement would have a delay of six months before pay rises took effect, Ms Harry said.

The NZNO wanted senior nurses and midwives to get a 4 percent pay rise effective from November this year, along with a lump sum of $350 for all NZNO members.