The United Firefighters Union of Australia (UFU) claims the dispute arose over the staffing levels at airports.

This includes Launceston Airport where several flights over the Christmas period arrived or departed without aviation rescue firefighters (ARFF) on duty.

However, Airservices Australia chief executive officer Jason Harfield said the union was using staffing levels as cover for a dispute about pay rises.

Secretary of the UFU's aviation branch Wesley Garrett previously told The Examiner the 23 firefighters employed at Launceston Airport were being pushed to the limit as more flights serviced the airport.

Mr Garrett said rostering had not kept pace with surging air travel after the COVID-19 pandemic, which had dire safety implications.

"Right now some airports around Australia are not meeting the minimum international staffing standards for a safe response to a critical incident," he said.

"Firefighters are short-staffed, fatigued and worried seeing Airservices Australia compromising safe staffing levels and thumbing their nose at the regulator."

ARFF staffing levels at Australian airports are set by legislation, with crews rostered on during airport operational hours.

Firefighters are not legally required to cover flights arriving or departing outside of these hours - typically due to delays, as was the case at Launceston Airport between December 2023 and January 2024.

Crew availability out-of-hours depends on overtime and fatigue management guidelines.

ARFF crews at Launceston are also supported by local fire brigades.

The Airservices Australia chief executive said the UFU was seeking to leverage the situation in order to secure higher pay - something he said would cost travellers an additional $128 million over three years.

"This threatened action in pursuit of a 20 per cent pay rise has nothing to do with staffing levels," Mr Harfield said.

"We have sufficient ARFF to meet our operational requirements, which are monitored and regulated by CASA as the aviation safety regulator.

"From the outset of negotiations in September 2023, Airservices has offered our ARFF crews an 11.2 per cent pay rise over three years, with no change in conditions."

Mr Garrett said a pay rise was one of the issues up for negotiation, but securing minimum staffing levels in future enterprise agreements was the "jewel in the crown".

Mr Harfield said the organisation would continue to negotiate with the union to deliver a "fair outcome" for ARFFs and the travelling public.

A ballot of union members counted on March 18 indicated 90 per cent supported industrial action, however strikes originally planned for the Easter long weekend were postponed.

Airlines would be given seven days' notice ahead of any industrial action according to Mr Garrett.