Paramedics say morale among their St John colleagues is the lowest they've ever seen it, and they hope a planned strike will help secure better working conditions.
The majority of First Union's 1100 ambulance members are said to have voted to strike - believed to be the first time paramedics in New Zealand have ever walked off the job.
It comes after a breakdown in negotiations with St John over negotitions around shift rates, some proposed salary cuts and changes to rosters.
Union organiser Sarah Stone said St John was still refusing to pay the 1.25 shift rate agreed to after bargaining last year, and the charity wanted to reduce the wages of dispatchers and call takers by up to $10,000 per year.
Additionally, Stone said during bargaining St John confirmed they wanted to remove minimum staffing levels, hours and places of work from the Collective Agreement.
"None of this is good enough, and First Union members are taking action after being taken advantage of by their employer for far too long."
She said ambulance crews voted to take full strike action, and the first 24-hour withdrawal of labour would take place on 25 November.
Trevor Hill is a paramedic in Hamilton and said the decision to walk off the job didn't come lightly, but crews were exhausted.
"We feel really, really undervalued, we feel St John don't really care."
Having been a paramedic for 12 years, Hill said he was paid $60,000 a year, but working an extra 12 hour shift every week he managed to earn around $90,000.
He said the extra pay that St John agreed to last year for shift pay would bring him up to around $90,000 a year - without having to work overtime.
"Instead of having to work 60 hours a week I would only have to be working 45 hours a week, and that would have a massive, massive impact on my family and my lifestyle."
Hill said when he filled in as shift manager he would send out more than 200 texts asking staff to work, and not get one response - which he put down to staff burnout.
St John believes its latest pay offer is an improvement - it's touting it as the biggest pay correction in the history of the ambulance service.
Deputy chief executive Sue Steen said the offer it had made to ambulance staff was significant - including 1.15 shift rates and committing to maintain predictable rostering arrangements.
She said if increased penal rates were awarded it would not be possible to offer other parts of the remuneration progression package.
"We are able to make this unconditional offer following confirmation by the government that they will provide a sufficient contribution to enable the full implementation of the independent pay review," she said.
Two ambulance workers' unions have taken the offer to their members for ratification - she said the issue over penal rates would be heard by the Employment Court next year.
Any industrial action must be undertaken in a safe and professional manner and St John is working to ensure there is limited negative impact to patients, Steen said.
Dr Ashley Bloomfield said Ministry of Health staff were trying to facilitate talks between the union and St John to resolve the issue, but he did not have any concerns for public safety if the strikes did go ahead.
"I know that both St John and the paramedics will work closely to ensure that public safety is not compromised. They all have a very strong commitment to that."