A $21 million cash injection into St John Ambulance isn't enough to contribute to staff pay, the CEO says.

Peter Bradley told The AM Show the funding, which will be shared over two years, is a one off stop-gap and can't be committed to long-term spending like wages.

"We've got an offer on the table for staff but clearly this is a one off payment, it's very hard to commit when that one is a one off."

St John is currently in negotiations with its ambulance staff and has seen industrial action such as staff writing on ambulances, refusing to wear uniform and not taking part in event work.

They've been offered a pay rise of 3.25 percent per year for the next two years.

"It's reasonable but its not what we believe our staff are worth," Bradley said.

"We want to pay them more than that and our funding bid to Government would give the opportunity to provide a bigger pay rise to our staff."

Bradley said the service is waiting to see if they get a more long term commitment from the Government, but until then they will continue fundraising for essential costs..

"What we don't want to see is the public having donate to run the day to day cost of having an ambulance service, paying our staff's wages, that's ridiculous."

St John and Wellington Free Ambulance will share the $21 million one off funds, as well as $17.2 million towards operational costs over the next four years.

The Government currently covers nearly three-quarters of the budget for St John, the country's largest ambulance service. It has to fundraise the rest - about $65 million a year.

Deputy Prime Minister Winston Peters said on Tuesday he believes that won't be the case forever.

"I am very confident that we can look forward to a day, not very far from now, where 95 percent of the needs of St John's are being funded from central Government."

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