The announcement came on the same day that Qantas - Jetstar's parent company - announced massive cutbacks to its operation as well amid the coronavirus pandemic downturn, with plans to ground at least 100 aircraft for up to 12 months and slash $15 billion in costs over the next three years.

Bob Toovey, Jetstar counsellor for the Australian Licensed Aircraft Engineers Association, said staff received an early morning email alerting them of a phone hook-up.

The hook-up from a senior maintenance manager lasted "no more than two minutes", telling staff their jobs were being cut.

"It was a one way conversation," Mr Toovey said. "The lack of compassion was probably what hurt the most.

"It was all over very quickly. He just told us that Newcastle was closing and that it would be gone by the end of the year.

"There was no talk about redundancies or relocation ... nothing like that."

The job losses include cabin crews, pilots and engineers. Unions estimate the total job losses will be about 220, plus others indirectly employed as part of Jetstar's operations at Williamtown airport.

But Mr Toovey said he was shocked by the decision because as recently as Monday he had been involved in a phone hook-up with senior managers where he asked the question directly whether there were any plans to relocate staff to either Melbourne or Brisbane - and the answer had been no.

It is understood a Jetstar spokesperson has since said the company would guarantee the apprentices' positions if they were prepared to move to Melbourne, but it was unclear how many other staff would be redeployed.

Mr Toovey said the level of professionalism at Jetstar in Newcastle has been viewed as "the centre of excellence" within the company.

"We have achieved well and truly up towards 100 per cent efficiency," he said. "You never get 100 per cent, but Newcastle's figures have always been excellent."

He said until the last six months the staff had always been "150 per cent engaged and motivated" and felt management had let the staff down.

He believes the way the announcement was made highlights this.

"It wouldn't have cost much to hire a small plane to fly one or two of the executives up to Newcastle to do this face to face and answer questions," he said.

Another employee, who asked not to be named, described Newcastle as the "'spiritual home" of Jetstar and said it was the company's best performing engineering and crew port.

"It is an incredibly professional workforce, and to be losing people of that experience and knowledge ... it's a very sad day," he said.

Qantas boss Alan Joyce announced it would slash 6000 jobs and continue to stand down another 15,000 as it struggles to cope with the effects of the coronavirus pandemic.

It will also ground at least 100 aircraft for up to 12 months and slash $15 billion in costs over the next three years. The job cuts amount to about 20 per cent of the company's workforce .

Mr Joyce said the cuts came amid the realisation that revenue will continue to be lower fro some time to come.

"We have to position ourselves for several years where revenue will be much lower. And that means becoming a smaller airline in the short term," Mr Joyce said.

"Most airlines will have to restructure in order to survive, which also means they'll come through this leaner and more competitive. For all these reasons, we have to take action now."

Qantas has cancelled all international flights, except for services to New Zealand, until late October.

Jetstar's Newcastle base was originally the headquarters of regional airline Impulse, which Qantas acquired in 2001.