Australian Workers Union boss Paul Howes has branded union officials found to be corrupt as "traitors", saying they need to be cut out like cancer.
Mr Howes used a speech to the National Press Club in Canberra on Wednesday to weigh into the issue of alleged corruption and misconduct in the Construction, Forestry, Mining and Energy Union, involving links with outlaw motorcycle gangs and criminals.
"Any union official proven to be engaged in corrupt or criminal behaviour is a traitor ... to our members they have betrayed, to our cause they have dishonoured and to our future they have undermined," he said.
The union movement should be "ruthless and uncompromising" on even suggestions of impropriety.
"If we turn a blind eye, if we ignore any pocket of dishonesty, it will grow like a cancer," he said.
"It is my job - and the job of every union leader - to cut that cancer out."
Those engaged in an "immature, Sopranos-style tough guy fantasy" were also unwelcome in the movement.
"We must never confuse strength with thuggery. Being a strong unionist is not about how many bikies you know," Mr Howes said.
However, he stopped short of endorsing calls for a royal commission or judicial inquiry into union corruption.
Rather than weeding out criminality, which is the role of police and the Australian Crime Commission, a royal commission would merely be a means for the government to "nobble the power of unions", he said.
The AWU has endorsed a call by unions for the government to set up an independent task force to look at specific criminal allegations.
