Jacinda Ardern called Simon Bridges "brazen" for criticising a lack of funding for St John, saying he "didn’t seek to resolve the issue" while in Government.
The exchange during Parliament's Question Time this afternoon came after the Government recently announced a funding boost for the ambulance service, but not full funding as requested.
"Is the reason why her Government can't fully fund the St John ambulance service because of the slowing economy and $600 million lower tax revenue?" Mr Bridges asked.
The Prime Minister answered by citing previous handling of the issue.
"I find it curious that the member is brazen enough to raise an issue that he did not seek to resolve.
"Obviously St John has continued to be part funded by successive governments including his own, at a rate of 75 per cent or so, we recognised that is an issue and want to ensure the sustainability of their funding.
"We have put in additional funding for St John while we work with them on a sustainable funding plan which is more than his government did," Ms Ardern replied.
Mr Bridges retorted that the last National government did offer resources to St John that have now been revoked.
"Did the last government fund double crewing of St John ambulance services and mental health resource on each ambulance that her Government cancelled?"
Ms Ardern didn't address the question directly simply stating that: "My view would be is that if everything is fine and dandy St John wouldn't have come to us."