Unions want a national inquiry into Australia's aviation future, after appealing against a partnership between Qantas and Emirates airlines to the consumer watchdog.
Tony Sheldon, national secretary of the Transport Workers' Union (TWU), along with other union representatives, fronted an Australian Consumer and Competition Commission (ACCC) conference on Friday.
Mr Sheldon said the conference demonstrated the need for government intervention into the partnership.
"During the one and a half hour hearing, the ACCC revealed that in their opinion an investigation into the impact of the proposed alliance on Australian employment did not warrant the resources," he said.
"Further to this, the ACCC admitted that they did not carry out any forensic investigation into claims made by Qantas that the international division is in terminal decline.
"We are calling on the government to establish a national inquiry into the future of the Australian aviation industry, which addresses the national interest and not just a narrow interpretation of what constitutes a competitive environment with slim reference to the public interest or benefit."
Qantas said the unions were out of step by pushing an "anti-Emirates line".
The airline said the ACCC had indicated it would give the green light to the partnership because of the benefits for consumers.
"Three-quarters of Qantas staff support the partnership, as does the federal government, state tourism bodies, our shareholders and our customers," Qantas said in a statement.
"We are pursuing this partnership as part of returning Qantas to international health."
Mr Sheldon argues the deal is bad for the travelling public, the economy and the Australian workforce.
Independent senator Nick Xenophon, who also went to the conference, agreed.
"We will see a shrinking of the flying kangaroo and further job losses," he said.
Earlier this month the ACCC gave Qantas and Emirates the green light to prepare joint strategies for sales, marketing and pricing.
But the ACCC has said its interim authorisation of the partnership may be reviewed at any time and should not be seen as an indication of whether final approval will be given or not.