The Australian Services Union has begun screening TV ads on what it says is a downgrading of service standards at the airline, which it hopes will be beamed straight into Qantas lounges across Australia.

"We thought we'd ratchet it up a bit," said the union's assistant national secretary, Linda White, of her union's fortnight-old campaign against the airline's cutting of check-in staff numbers and minimum wage standards.

Ms White said the advertisements running on SkyNews were aimed at Qantas's most loyal customers. They were timed to air in the evening when the Qantas Club lounges are full of peak-hour travellers.

The ads feature a kangaroo and urge the public to complain directly to the Qantas chief executive, Geoff Dixon, over the levels of service at the airline. The ads were launched on YouTube early this month.

The union represents one-third of Qantas's workforce, including check-in, call centre and IT staff. It says that the recent breakdown of enterprise bargaining talks with the airline could lead to strike action.

"We can't rule out industrial action, I'm afraid," Ms White said. "They are refusing to budge."

Qantas declined to comment on its wage discussions with the union, nor would it respond to the union's charge that it had reduced the minimum base wage for check-in "hosts" from AU$34,716 to AU$31,386 a year.

"They are suggesting paying people less than they pay people at Jetstar," Ms White said.

Qantas says the hosts - who are hired to help passengers use self-service check-in counters - are less skilled than check-in counter staff.

The union says that although Qantas is making record profits and carrying record numbers of passengers, it is leaving its airport check-in counters undermanned.

The union says Qantas has slashed its check-in staff by 450 to about 2500 since 2001.

Ms White said there was an incident at Sydney Airport early this month when 200 passengers were waiting while Qantas had only one check-in staff member manning the counter.

Qantas is believed to be considering hiring check-in hosts in Sydney and Melbourne to ease congestion.

Qantas's executive general of people, Kevin Brown, said the airline is keen on striking a deal with the union.

"The EBA negotiations are constructive, but they seem to have slowed up recently," Mr Brown said.