Qantas will face its first hurdle after dangling an axe over the jobs of 5000 workers, with one union taking the airline to Fair Work Australia.

The Australian Services Union NSW branch represents Qantas International check-in staff, who say their jobs were put on the line without any prior consultation.

The union alleges Qantas may have breached its legal obligations to the 230 check-in staff at Sydney Airport.

“We're shocked by this,” Australian Services Union NSW secretary Sally McManus says.

“Qantas has legal obligations to talk to the workers [and] their union before making such decisions and we're extremely concerned,” she added.

“We believe that they've been very clear, saying they're going to offer redundancies to all of their full-time staff. They've actually put that in writing.

“This goes against what the CEO said ... he announced there would be job losses but he said they had to consult with the unions first,” she said.

Meanwhile, on a national level, Qantas is continuing to lobby the Federal Government to either provide a debt guarantee to solidify its financial outlook or change the Qantas Sale Act to allow a great proportion of foreign ownership.

Prime Minister Tony Abbott has all but buried the chance of a debt guarantee, it seems, but did last week describe the Qantas Sale Act as “a ball and chain”.

Nationals leader Warren Truss and other Coalition hardliners appear sceptical of the airline’s claims that so many jobs need to go. Mr Truss says he is not keen on supporting efforts to overhaul the foreign ownership rules.

Opposition leader Bill Shorten wants to keep Qantas mostly Australian-owned.

“Labor is prepared to work with the government on Qantas - the issue is too important for political games,” he said in a statement.

“But Labor will not stand by and let Tony Abbott send Qantas jobs overseas. This is Australia’s airline and it should remain in Australian hands.”

Opposition treasury spokesperson Chris Bowen has a more variable stance.

“We'd look at any proposal sensibly, but the 51 [per cent Australian ownership] / 49 [per cent foreign ownership] is a red line for us,” Mr Bowen said over the weekend.

“Certainly Qantas having access to more capital generally is not a bad thing, provided that 51/49 rule is maintained.”