"However, this new proposal would introduce an element of uncertainty that would make planning for current workload and future growth in demand for services a lot more difficult. We will effectively be competing with other organisations for a slice of the pie, and we are concerned that this will lead to an inevitable reduction in funding for NEST.
"Any future funding of NEST would be at the sole discretion of the council and not ratepayers.
"We are extremely grateful for the level of support we receive from our community and have always believed that the NRC targeted rate allows for the cost of the service to be spread more fairly across the region," he added.
"That's why we support a continuation of the existing guaranteed rating structure. It allows the trust to concentrate on running an air ambulance service instead of having to constantly worry about fundraising."
The NRC contribution covered about half of NEST's annual shortfall in government funding, the balance coming from donations and sponsorship.
Mr Ahlers also noted that the trust had experienced a constant increase in demand for its services over recent years. Last year the helicopters flew 735 missions, transporting 800 people to hospitals or medical facilities around the North. On average they were in the air twice a day.
"We are already extremely economic with our operations, and have introduced a number of initiatives in the last couple of years to reduce costs and generate revenue," he said.
"The flight simulator introduced last year to train our pilots is a good example of this. But this will not nearly cover the shortfall posed by a drop in or lack of council funding.
"We hope the council values the service we provide and reconsiders this proposal. If we don't have certainty around funding we may be forced to review the level of service we can offer, which is currently 24 hours a day, seven days a week, every day of the year."
The council is calling for submissions to the proposed changes under its draft long-term plan document, closing at 3pm on Friday next week (April 24).