Grey Power is horrified at plans by St John to cut its emergency response to minor 111 calls.
The ambulance service, which it says covers 90% of New Zealand, is grappling with funding shortfalls of $15 million a year.
St John says it will be reducing services for the 10 to 15% of calls which concern minor conditions such as allergies, animal bites, back pain and cuts.
A forthcoming pilot programme in Canterbury will involve the referral of patients to GPs and other medical services, or treatment by a single paramedic sent out in a car.
Grey Power has labelled the plan appalling, saying elderly people with genuine health issues will be put off from calling for assistance because of fears they will be fobbed off.
It says some of the complaints labelled as minor by St John, such as falls and abdominal pains, are particularly problematic for older people.
St John is staffed by paid and volunteers and says callouts are growing by 4.5% per year, mainly due to an ageing population with chronic medical conditions.
In 2011, the service received a record 337,000 emergency callouts.