The union representing New Zealand's ambulances says the "fragmented" service needs to be streamlined into one national body.
National Distribution Union ambulance sector coordinator and union organiser Craig Page said there are real problems arising from lack of funding and overall government ownership.
He said funding streams remain fragmented despite the Government creating the National Ambulance Sector Office, a joint venture between ACC and the Ministry of Health.
"To fix the issues within the ambulance sector we need one provider nationally, legislation, regulation of the sector including non-emergency and event operators," Mr Page said.
A spokeswoman from the Ministry of Health said the National Ambulance Sector Office managed the ambulance contracts for both agencies, and leads the consultation on the draft New Zealand Ambulance Service Strategy to find a sustainable way to fund the service.
"This requires consideration of different purchasing methods, and legislative requirements. There is a programme of work underway to define the changes required, and to identify suitable funding models," she said.
Page said the service needs better targeted funding to performance, more vehicles, more career paramedics and a better network of stations.
"The current system of four public operators and a number of secondary private, non-emergency providers is not acceptable."
He said a fragmented national operation leads to competitive behaviour, slow progress to achieve consistency and creates needless duplication of functions such as IT and administration.
The ministry spokeswoman said providers are working to develop consistency across all services.
"The Emergency Ambulance Communications Centres, which are owned and operated by two providers, already have common technology across the three centres and act as a virtual single centre," she said.
St John external communications manager Ali Tocker said the fragmented nature of the service is a feature of its historical nature of the service, when different stations were set up according to the needs of the community.
"That's partly why ambulance services have different providers," Tocker said.
She said issues of a single national provider were put to a select committee hearing in 2007 and a decision was made at that time not to streamline the services.
"It's not our decision, that's for the government to decide," she said.
The ministry said the history of ambulance services is that they have been provided by non-government organisations which are not owned and operated by the government.
Tocker said "the bigger picture is that ambulance does not receive adequate funding".
Ambulance services typically run an annual shortfall of $12 million, she said, meaning the service has to continue to fundraise to meets its requirements.
St John said in December that 34 new paid ambulance officers joined the force, with another 51 new paid officers starting work between January and June 2010 as part of a package of targeted government funding.
In a statement, St John Chief Executive Jaimes Wood said "we recognise that this is only a step to increase double crewing rates and reduce on-call responses, and that these 85 positions do not fill every need".
A spokeswoman from the Ministry of Health said 100 new paramedics will be added to frontline emergency services over the next four years in a $28 million investment.
St John ambulances cover about 85 per cent of the country, with the rest of the services provided by Wairarapa District Health Board, Taranaki District Health Board and Wellington Free Ambulance.