Union boss Sally McManus has put corporations on notice following a High Court decision against Qantas, warning workers are prepared to fight for their rights.
Australia's highest court dismissed an appeal by Qantas against a ruling it had illegally sacked almost 1700 workers during the COVID-19 pandemic.
Former employees will pursue compensation and penalties in the Federal Court, with a hearing to be held in Melbourne next Wednesday.
Ms McManus said she wanted to see workers fairly compensated, but would not specify what that looked like.
"There is the mental trauma people have gone through which was significant for lots of them," the ACTU secretary told ABC radio on Thursday.
"That will have to be carefully worked through."
Ms McManus praised the Transport Workers Union for risking the consequences of losing the challenge.
"When you stick together you can achieve things," she said.
"Hopefully, it is a message to corporate Australia that working people in Australia have still got fight and that if this happens, we will take it on."
Nationals leader David Littleproud said it was clear the carrier did the wrong thing and noted new Qantas boss Vanessa Hudson was chief financial officer at the time.
"There are serious cultural deficiencies at Qantas," he told Nine's Today show.
"There are serious questions that need to be looked at ... the board needs to act swiftly, or themselves step aside."
The airline had sought to overturn two rulings made by the Federal Court that the outsourcing of baggage handlers, cleaners and ground staff was unlawful.
It argued the decision to outsource the remainder of its ground handling function was made in August 2020, when "borders were closed, lockdowns were in place and no COVID vaccine existed".
The airline lost billions of dollars during the pandemic.
Qantas said in a statement on Wednesday it deeply regretted the personal impact the outsourcing decision had on all those affected and sincerely apologised for it.
Opposition transport spokeswoman Bridget McKenzie said former Qantas chief Alan Joyce and Ms Hudson were at the "top of the list" to be called to give evidence at a Senate inquiry into the government's decision to reject Qatar Airways' request for additional flights.
"The reputation of this once-proud national carrier has absolutely been tarnished," she told Sky News.
Public hearings are expected to start next week.