Fire and Rescue NSW says the loss of their on-call helicopter, which was in high demand during the 2013 Blue Mountains bushfires, is "a concern".
But the Police and Emergency Services Minister Stuart Ayres says there is no cause for concern with plenty of aircraft available to cover a disaster at short notice.
A story in The Sydney Morning Herald last week said that the sale of an "essential" helicopter has left firefighters under equipped. It means the nation's busiest firefighting force does not have dedicated aerial support.
Trish Doyle, Labor's candidate for the Blue Mountains, said "FRNSW cannot afford to be left without this sort of helicopter," calling it a "blow" to the Blue Mountains.
"FRNSW deserves to have dedicated air support, and not have to rely on other sources to provide an aircraft able to move into action," Ms Doyle said.
"Given the sort of bushfires we have seen in the last two years - ones that flare up extremely quickly and take off due to the dry, windy early Spring conditions - FRNSW cannot afford to be left without this sort of helicopter."
Ms Doyle said it was a "blow to the confidence Blue Mountains residents have in Fire and Rescue NSW being able to support our fantastic on-the-ground firefighters."
The Fire Air 1 helicopter was formerly shared between NSW Police and FRNSW. The ageing craft was decommissioned in June last year. It has been mothballed and will be sold.
The fire service used the helicopter to transport equipment and personnel, carry out reconnaissance, water-bomb fires and winch people from floods.
FRNSW says the aviation capacity it provided was "essential" to its emergency response.
However, FRNSW's latest annual report said the arrangement "will not be able to replace the former capability" and "the loss of a partially owned on-call aviation asset is a concern".
The spokeswoman said the Westpac helicopter deal covered most of the fire service's needs, but the aircraft could not carry out water bombing and "may not always be available when required by FRNSW" because it would prioritise rescue missions.
"Because the aircraft are 'on-call' rather than a permanent resource, FRNSW no longer has permanent crew assigned," she said.
Fire Brigade Employees Union state secretary Jim Casey said firefighters "take any erosion of our operational capacity very seriously".
"For the largest fire service in the southern hemisphere to not have aerial support is frankly ridiculous," he said.
But Emergency Services Minister Stuart Ayres said the NSW State Air Desk had more than 100 aircraft available to Fire and Rescue NSW and other emergency services "which can be called upon at short notice".
He said the Westpac helicopter agreement covered the majority of FRNSW's needs.
"There is no reduction in aviation capabilities of fire services across the Blue Mountains or anywhere in NSW," he told the Gazette.
"The Blue Mountains is served by the State Air Desk with over 100 aircraft including a mixture of fixed wing and water bombing helicopters.
"We also have at our disposal the two heavy air cranes which we lease each bushfire season ready to go at a moment's notice as seen in the Warrimoo fires in November.
"The State Air Desk ensure we have diverse range of aerial appliances available to fight fires across the Blue Mountains and all of NSW."
