Health Workers Union boss Diana Asmar allegedly claimed so-called "traitors" would regret betraying her, a couple of weeks before five staffers and two officials were stood down.
Lawyers for the national union (HSU) made the allegations in the Federal Court on Monday as they sought more restrictions on Ms Asmar's role in its Victorian branch.
The interlocutory application is part of a broader push by the HSU to have administrators appointed to the state branch, called the Health Workers Union.
The HSU claims the branch is dysfunctional after the Fair Work Commission alleged Ms Asmar falsely claimed more than $120,000 as relevant business expenses.
Justice Craig Dowling made orders on October 7 limiting Ms Asmar's powers, including preventing her from dismissing any employees or altering their employment.
Ms Asmar made an undertaking to the court that she would follow the judge's orders.
But HSU barrister Malcolm Harding SC told the court Ms Asmar made a speech at a delegates conference on October 23, saying there were traitors in the union who would regret betraying her.
Two union officials from the Victorian branch were then stood down and five call centre workers dismissed on November 11.
One of the officials had openly said Ms Asmar should step aside because of the Fair Work allegations, Mr Harding said.
All five call centre workers were recruited by the other dismissed official, the barrister said.
Mr Harding claimed under union rules, Ms Asmar was the only one with the power to terminate someone's employment.
"She was telling delegates there were traitors in the union and she would get them," Mr Harding told the court on Monday.
"She has given affect to that threat."
Mr Harding claimed Ms Asmar had breached her undertaking and the judge should make further orders restricting her.
The barrister said the status quo at the Victorian branch needed to be preserved while the HSU's case was before the court.
But Ms Asmar's barrister Rishi Nathwani KC argued there should not be any changes because his client has not breached any of her court undertakings.
"She has not dismissed anyone, nor has she procured anyone to be removed," he told the court.
The branch's committee of management could also dismiss employees, Mr Nathwani said.
Justice Dowling will make a decision on whether to impose further restrictions at a later date.
