Workers have downed tools and gathered across major cities in their thousands to support the CFMEU amid action to crack down on bikie infiltration.
Members and fellow workers including from the electrical trades, maritime and manufacturing unions marched through major cities on Wednesday to express their anger over the federal takeover of the Construction, Forestry and Maritime Employees Union.
The union's construction and general division has allegedly been involved in criminal and corrupt conduct, recently uncovered by Nine newspapers.
More than 10,000 arrived at Trades Hall in Melbourne at 10.30am before marching down LaTrobe Street, closing the major thoroughfare and causing tram disruptions.
Marchers chanted "union strong" and wore slogans including "God forgives but the CFMEU doesn't".
Electrical Trades Union representative Troy Gray accused politicians of trying to stop workers getting pay rises.
"The same politicians that fist pumped the air when they put the CFMEU into administration just gave themselves a pay rise," he said.
Victorian Workplace Relations Minister Gabrielle Williams urged those protesting to do so constructively.
"While we respect your right to protest, we would urge you to do it lawfully and to do it peacefully while you have and we all enjoy a right to protest," she told reporters.
Several thousand demonstrators descended on Belmore Park in Sydney from 11am before marching through Hyde Park and settling outside NSW parliament.
Former CFMEU NSW secretary Darren Greenfield addressed the sea of high-vis, saying "every decision made by (the CFMEU) is to benefit our members".
Greenfield and son Michael, a former state branch assistant secretary, are accused of accepting bribes from a building company for preferential treatment from the union and access to contracts, spanning as far back as 2018.
Both are on bail on charges first brought in 2021 that have recently become the subject of intense interest following an investigation into alleged union corruption by Nine newspapers.
Greenfield told the crowd lies were being spread about him.
"People have been trying to muddy my name for 45 f***ing years," he said.
Employment and Workplace Relations Minister Murray Watt told the National Press Club the culture across parts of the construction needs major changes.
"A safe workplace is also one that is free of corruption, criminality, bullying and violence," he said,
"Sadly, recent allegations strongly suggest that kind of culture has seriously infiltrated the construction division of the CFMEU and the wider construction industry.
Mr Watt said there was an opportunity for "once in a generation" change across construction including by reinvigorating the National Construction Industry Forum.
"I will be bringing the forum together in the next month and we will broaden its membership," he said.
"We will discuss a range of difficult issues and it will require each side to give and take, including by addressing misconduct and lawlessness on both the worker and employer sides."
More than 60,000 workers rallied across the country on August 27.
CFMEU administrator Mark Irving has promised detailed investigations to expose the grip outlaw motorcycle gangs and organised criminals have on the union's construction arm.
After receiving a damning report into the Victorian branch, which indicated it was laden with violence and intimidation, he committed to establishing an integrity unit in Victoria.
Other branches in NSW, Queensland and South Australia will also be scrutinised over the extent of bikie and organised crime involvement within their construction industries.
Questions around whether union officials breached conflicts of interest by accepting unlawful kickbacks and secret benefits as well as transfers of funds to and from the union, including the use of charity trusts, will be under the microscope.
