Hundreds of people are putting their support behind nurses as they fight for better pay.

The New Zealand Nurses Organisation's rejected a pay offer by district health boards as it negotiates for a multi-employer collective agreement.

It's started a campaign called 'Health Needs Nursing' and called on the public to volunteer and send letters to the Government.

NZNO Industrial Services Manager Cee Payne says they've been overwhelmed with the support.

"We're having thousands of postcards being sent to the three Labour government ministers. And we've got hundreds of people volunteering, probably 50 every four hours."

She says it's great to see the public recognise that nurses deserve more than the status quo.

"Very high workload. Increasing patient acuity so people are coming into the hospital sicker. Nurses are stressed, fatigued, and we've got low morale and high staff turn over."

Currently, strike action is still on the table if the DHB and NZNO cannot reach a better agreement.