In his decision on Monday, Justice Snade said the CFMMEU "is a serial offender that has, over a long period, exhibited a willingness to contravene workplace laws in the service of its industrial objectives; and one that appears to treat the imposition of financial penalties in respect of those contraventions as little more than the cost of its preferred business model".

Attorney-General Christian Porter appointed Justice Snade, a former junior barrister and Liberal Party student politician, to the Federal Court in February.

While addressing what he said was the union's unflattering history of workplace law contraventions, Justice Sneddon said he did not "not relish the prospect of adding my name to the long list of judicial officers whose exasperated admonitions appear to have been met with studied indifference".

He cited Mr Setka's public dismissal of judges who “call us criminals [and] all sorts of things [and] fine us millions of dollars [despite having] probably never done a day’s work in their li[ves]”:

The court heard that CFMMEU shop steward Kevin Pattinson had asked an apprentice and an electrician whether they were members of the union at a construction site in the Melbourne suburb of Frankston in September last year and stopped them from working when they said no.

Justice Snade fined the union $63,000 and Mr Pattinson $6,000 to be paid out of his own pocket for preventing the two workers from doing their jobs of installing solar panels. Mr Pattinson had misled the workers when he said they needed to join the union to work on the Multiplex student accommodation project for Monash University.

Australian Building Construction Comission deputy commissioner Matt Kelleher said all workers have a legal right to choose whether or not they want to become a member of a union.

“Workers cannot be prevented by union officials or anyone else from working on an Australian
building and construction site because they are not a union member," he said.

"It is regrettable that [CFMMEU] members’ hard earned money continues to be used to pay for this unlawful conduct.”

A Senate inquiry will deliver its findings into the federal government's proposed Ensuring Integrity law within two weeks. The legislation would give the minister for industrial relations, the Registered Organisations Commission and any party with“sufficient interest” the power to apply to the Federal Court to deregister a union.

The CFMMEU and its controversial Victorian boss John Setka have boosted the federal government's chances of getting the legislation passed in the Senate. Independent Senator Jacqui Lambie has vowed to support the Ensuring Integrity bill unless Mr Setka quits as Victorian state secretary.

Mr Setka has repeatedly refused to resign from his union leadership despite pressure from the Labor Party and the Australian Council of Trade Unions and he is appealing a supreme court decision that permitted the termination of his Labor Party membership.