Unions have criticised what it called "misleading and baseless threats" from the Fair Work Ombudsman after workers walked off the job in solidarity with the Construction, Forestry and Maritime Employees Union (CFMEU).
Tens of thousands of workers downed tools and marched through the streets of the nation's capital cities on Tuesday, after hundreds of CFMEU officials were sacked when federal Attorney-General Mark Dreyfus placed its construction and general divisions into administration.
Ahead of the rallies, the ombudsman warned those who failed to turn up to work or left without permission could be in breach of workplace laws.
After the marches, the ombudsman encouraged employers to notify the ombudsman about any "potential unlawful industrial action at their workplace".
"There is no place for unlawful workplace behaviour," it said.
Employers are legally required to deduct four hours of pay if people take unprotected action, even if they were gone for less than that time.
Allen Hicks, secretary of the Electrical Trades Union NSW/ACT, said workers had united to protest over what they believed was an attack on basic workers' rights and procedural fairness.
"It wasn't industrial action and to describe it as such is deliberately misleading at best," he said.
Workers rallying in Melbourne on Tuesday. Source: AAP / Joel Carrett
"Misleading and baseless threats like these are exactly why workers need unions who can defend their basic rights."
Protesters said the administration — which was enforced in the wake of allegations of links between bikie and criminal gangs and the CFMEU's construction arm — was an attack on democracy and an "act of treachery".
Prime Minister Anthony Albanese said it was in the interests of all trade unionists to have organisations free of corruption.
CFMEU Rallies: 'This union will stand long after politicians are gone'
Master Builders CEO Denita Wawn said the association has been calling for action against the CFMEU for decades, and that the government had shown leadership.
"We need a strong union, but one that is lawful," she told Nine's Today program on Wednesday.
"We're only in the third day of administration.
"The ALP has, obviously, not done this lightly, but they've shown some leadership to ensure that we have a lawful union."
Opposition workplace relations spokesperson Michaelia Cash blamed the rallies on the government's handling of the administration process, which was backed by the Opposition.
