Teri O'Toole, from the Flight Attendants Association of Australia appeared with Qantas international cabin crew at a media conference on Thursday.
Flight attendants had been on the frontline during the height of the pandemic and had "volunteered to bring your family home during COVID-19", she said.
"They put their own lives at risk because right at the beginning there were no vaccinations … they went into hotspots to bring people home," she said.
Many had been isolated in Howard Springs isolation camp for "months at a time".
Those Qantas flight attendants now face the choice of being terminated, or taking contracts at award wage, for many meaning a pay cut of up to 50 per cent, the ACTU says.
Qantas disputes the claim.
"It's disingenuous to say that Qantas wants to cut pay and conditions, given we put a four year deal on the table that offered more than six per cent pay increase and higher allowances," Qantas said in a statement.
Rachel Yangoyan, Qantas executive manager of customer experience and operations wrote a note to long haul flight attendants last month saying some clarifications had been made to the wording of the agreement.
The clarifications were around fatigue management and crew availability requirements, and had been discussed with Qantas, QF Cabin Crew Australia and the FAAA, and, other than this, the EBA remained the same, Ms Yangoyan said.
"This is a positive outcome for everyone and an important step in securing the critical changes we need to support the recovery of our international business."
Qantas said it could not "pick and choose" which parts of the agreement were thrown out in order to meet its rostering requirements.
"Termination of the agreement would see crew revert to the modern award, which is the safety net for the industry, while a new agreement is negotiated."
The agreement will be put to a vote again within weeks.
Qantas Group Executive Andrew McGinnes said it was the "first time in Qantas' history that it has sought to terminate any EBA and it followed intensive engagement with the FAAA for a new agreement that ended in a deadlock".
"In short, we need changes to our agreement with long haul crew to ensure that our international business can respond quickly to a market that is going through a very complicated restart," he told a senate inquiry on Thursday.
It was "never about" reducing pay for Qantas crews, he said.
When the union took a version of its enterprise bargaining agreement to Qantas at the end of 2021, it was voted down with 97.4 per cent of workers rejecting the deal. Following that, Qantas applied to terminate the agreement, Ms O'Toole said.
Some months later, in February the FAAA reached a deal with Qantas to support the EBA.
The current system, which allows businesses to throw out entire agreements, was unfair, she said.
"We need a government that does not allow business to trash its employees," Ms O'Toole said.
"These people were paid to stay, to be loyal, to come back to flying so that we would not lose years and years of experience.
"But what we are doing now is having a gun to our head – this is not a negotiation."
ACTU President Michele O'Neil said Qantas was trying to "use our laws to cut workers wages".
"This is shocking because these workers have done so much through the course of COVID-19."
Qantas workers had been "stood down for very long periods of time" and later been asked to "volunteer to rescue" Australians who were stranded because of the pandemic.
