Aviation firefighters are preparing to stop work at airports across the nation next week but it is unclear if their claims about safety stack up and if flights will actually be grounded.

The United Fire Fighters Union says every firefighter at the 27 national airport fire stations across the country will stop work for four hours from 6am to 10am on December 9.

The 27 airports include major international airports Sydney and Melbourne. 

The head of the union's aviation branch, Wes Garrett, said the firefighters were striking as part of an industrial relations dispute with government body Airservices Australia.

Airservices Australia is responsible for the safe and efficient management of Australia's skies and the provision of aviation rescue firefighting services, according to its website. 

The government-owned body's spokesperson Dominique Lamb told ABC News that it anticipate that flights will continue if the strike goes ahead.

"We will do everything we can to minimise risk," she said.

ABC News understands that, if the strike goes ahead, it will come down to the airlines' decision about whether to fly.

The major airlines have been contacted about whether they will reschedule or cancel flights due to take off or land during the four-hour planned strikes.

December 9 is the day before school holidays start in Queensland. 

Ms Lamb said Airservices was "disappointed" by the timing of the strike.

"It's quite clearly the Christmas period," she said.

Australia's biggest airport is urging the government body and the union to resolve their dispute before the planned strike goes ahead.

"We urge (them) to get back to the negotiating table and find common ground so that passengers aren't disrupted coming into the busy holiday period," a Sydney Airport spokesperson said.

"We will have extra staff on the ground next Friday to help passengers and are recommending that people follow the advice of their airline regarding the status of their flight."

Why are the firefighters planning a strike?

The union claimed this morning that Airservices Australia cut 100 aviation firefighters from Australia's airports in October 2021.

"Every day the lives of 2,500 air travellers across Australia are being put at risk because they don't have the protection they need from understaffed aviation firefighters," Mr Garrett said.

"Air travellers don't have the protection they need because Airservices cut 100 aviation firefighters from Australia’s airports to cut costs in October 2021."

However, Ms Lamb said those job losses were voluntary redundancies after a call-out for people who wanted to step down from their jobs.

She said some of those 100 people had been replaced and recruits were coming through. 

She added that safety audits had been done by the government-owned Civil Aviation Safety Authority (CASA).

A CASA spokesperson said Australian regulations for airport firefighting services specified "the number of trucks, response time and the amount of foam that can be delivered".

They did not specify how many firefighters were required, the spokesperson added.

Union accused of playing 'politics' with safety

Aviation specialist Ron Bartsch said Australia was obliged to comply with international standards on airport safety.

"The bottom line is, and what the public should know is, that safety will not be compromised."

However, recently retired aviation fire commander Trevor Rodgers told a press conference this morning that firefighter shortages could have catastrophic consequences for the passengers of a burning aircraft.

"After that three-minute period of time, the fire penetrates the cabin and the chances of people surviving a major crash internal fire is greatly reduced."

Airservices' spokesperson Dominique Lamb added that the strike was "quite clearly" about a dispute about pay.

"We've been at the negotiation table for 18 months, and this is really over a 15.5 per cent pay rise," she said.

"We're hopeful they will return to work and cease strike action."