Ambulance officers say an offensive ad urging people to donate to St John highlights years of under-funding, and are repeating calls for full funding from the Government.
Hundreds of paramedics complained about the ad because it implied funding would go directly to Christchurch staff who treated people injured in the terror attacks. The ad has now been pulled.
First Union's national ambulance co-ordinator Sarah Stone told Kate Hawkesby police and fire crews don't have to fundraise like St John does.
"It's very difficult to run a service, the way they do run it, when you only get paid 73 per cent of what you need to run the services and this means that inevitably workers' wages are hit."
She said St John didn't mean to cause offence but are "woefully underfunded".
"St Johns' response was that they did it because people were asking how they could donate...after they had seen the fantastic work and first class service the workers provide."
"Workers are struggling and the service is struggling to retain workers."
However, Stone said a number of paramedics felt it was insensitive and that it implied the money would have gone directly to the frontline workers.
"Paramedics in Christchurch, those who attended the scene and who know colleagues, family and friends who were affected by the awful events, but also paramedics around the country feel for their colleagues and Christchurch and felt that, at the least, it was an extremely incentive thing to do."
"I think there was also anger that the advert implied in some way that the money would go to those paramedics in Christchurch and that's not how the funding is structured."
She said the money would go into the service but that there's "no way" it would have been allocated into staff wages.
This incident highlights the issues St John has with underfunding, Stone said.
"What it means at the moment is that the service is actually facing a crisis in New Zealand. It's running under establishment which means that it often can't fill the ambulances it has and put them on the roads. So what we are finding is ambulances will be left at the stations because they don't have the staff to fill them."