South Eastern Sydney Illawarra Area Health's patient car fleet is to be cut by 10 per cent under a NSW Health mandate to "streamline" community-based care.

Area Health said the arrangements would "unlock resources enabling them to be redirected to frontline clinical services", and that patient care would not be compromised by the reduction in resources.

But NSW Nurses Association Illawarra representative Angela Pridham attacked the plan, saying standards of patient care would deteriorate if nurses had limited access to transport.

"There were already concerns there weren't enough cars to go around," Ms Pridham said.

"It's typical that people who sit in an office and don't actually have interaction with the patients and don't know what community nurses do think that a reduction in resources will not impact on patient care."

Of the area's 950-car fleet, between 45 and 50 per cent of vehicles are used to visit patients in the Southern Network.

Among those who rely on the service are early discharge mental health patients, the elderly and new mothers, who free up hospital beds by having dressings changed, assessments done and follow-up care administered in their homes.

The cars are also used to transport clients who cannot make their own way to appointments.

"We don't have enough beds in NSW and we don't have enough nurses, so the Government's answer to that was to put hospitals in the home and make more community-based services," Ms Pridham said.

"Now they're depleting the resources from the community. Patients get discharged ... early because there's supposed to be a community-based service, but the community-based service will have limited access to the patients.

"I think the Government needs to look at this - they will see patients returning to hospital because they haven't been able to be looked after properly - and we haven't got enough beds now."