CFMMEU ACT branch secretary Jason O'Mara has lost his right to enter building worksites after the Fair Work Commission revoked his access permit.
Mr O'Mara, the union, and five other officials were fined more than $200,000 last September for breaching Australia's right-of-entry laws in 2013.
Right-of-entry permit holders can enter worksites for certain reasons, including for example, union officials to speak with workers and investigate possible breaches of workplace laws.
But Mr O'Mara had refused to produce his federal entry permit when asked.
Then showing what Fair Work called a "flagrant disregard" for safety rules he dismissed the rule that there needed to be a person accompanying any visitor to the site.
He told the builder that they needed "learn the rules and legislation on the rights of a permit holder because [they] have got it all wrong", that he could go on site and "not be accompanied", and the "two-person visitor rule" was not reasonable and did not comply with the law.
The judge found these were all misleading statements.
"To profess knowledge, and to act bluntly and forcibly upon it, when it is plainly wrong, is (and in this instance was) wilful and dangerous ignorance," Justice Warwick Neville said in the Federal Circuit Court decision.
This week, Fair Work announced it had suspended Mr O'Mara's right to entry permit.
In a statement published online by the Australian Building and Construction Commission, fair work deputy president Val Gostencnik said Mr O'Mara's actions were not trivial or inadvertent.
He said the experienced union official should have set an example "to be civil, properly informed and knowledgeable, and reasonably skilled in negotiation with on-site managers."
Mr Gostencnik also dismissed Mr O'Mara's recent training on his union official duties.
"... [W]ithout some indication of regret or remorse for the conduct resulting in triggering events, what confidence can be garnered that the kind of conduct which led to the triggering events would not be repeated?"
The union and Mr O'Mara are currently before the ACT Magistrates Court accused of pushing Canberra businesses into a cartel.
They have pleaded not guilty and are fighting the case's committal to the Supreme Court for trial.
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