Australia's flagship airline, Quantas, is expected to cut hundreds of employees when it discloses its half-year results on Thursday, the nation's Herald Sun newspaper reported.

Quantas, the oldest continuously operating commercial airline in the world, has been financially struggling and been scrapping unprofitable routes. Last year it cut 1,000 jobs.

The jobs of some 1,460 maintenance workers are expected to be put under review as the company contemplates closing as many as three of its heavy maintenance bases.

In addition, the airline will also announce it is laying off hundreds of other employees, including flight and back-office workers, the Herald Sun said.

Quantas said it will not go outside the country for heavy maintenance work, something union workers fear.

Any suggestion that Qantas is 'offshoring' jobs is totally incorrect. We remain the only airline in the world that has established heavy-maintenance and engineering facilities in Australia, said CEO Alan Joyce. 

Such reassurances have little impact on union leaders.

The secretary of the Australian Council of Trade Unions said job cuts at Qantas will not be a surprise.

Ever since the dispute last year it's been pretty clear that Qantas was intent on restructuring operations and cutting jobs, Jeff Lawrence, secretary of the Australian Council of Trade Unions, said. And so it's a concern and when you add it to some of the other things that have been happening in the job market it does show that we've got some challenges at the start of 2012.

The prospect for widespread layoffs troubles Australia's government as well as its unions.

Employment Minister Bill Shorten said too much cutting could endanger the country's base of skilled workers.

You can cut too much and then lose skills that are never coming back, he told ABC Radio on Thursday. And there will be a time when we need skilled engineers.