Blackmail charges brought against two construction union bosses accused of threatening Boral executives at a Melbourne cafe, have been dropped by prosecutors.
CFMEU state leader John Setka described the decision as a win for workers, and accused the coalition government of conspiring in a bid to criminalise unionism.
Setka and his deputy Shaun Reardon were fighting allegations they blackmailed Boral managers Paul Dalton and Peter Head at a coffee shop meeting in Melbourne in April 2013.
It was alleged the pair threatened to blockade Boral plants and trucks if the company refused to meet union demands.
But prosecutors dropped the charges on Wednesday during a pre-trial hearing in Melbourne Magistrates Court.
"After a careful assessment of the evidence, I have instructions to withdraw the charges against both accused," prosecutor Ray Gibson said.
Setka and Reardon will not seek to have legal costs paid by the state, the magistrate heard.
They were charged in 2015 after an investigation by a joint Victorian and federal police unit, following a referral by the Trade Union Royal Commission.
Outside court, the pair's lawyer Peter Gordon called them "innocent men", who were the victims of distortion and destruction of evidence.
"One coffee shop conversation about work safety at (building giant) Grocon got distorted, and it got fabricated into a blackmail threat," Mr Gordon said.
"Neither of Boral's men took the coffee shop conversation as any kind of threat at the time."
Setka accused the coalition government of conspiring against the union in an attempt to criminalise union activity.
"It's definitely a witch-hunt," he told reporters.
"You've got all sorts of organisations that were involved in this conspiracy.
"It was to criminalise trade unionism in this county. That's all it was about."
He said the government was "all across" the case from the start and there had been talks involving former prime minister Tony Abbott and former Victorian premier Denis Napthine.
"It was proven in court that there was communications between Tony Abbott, Eric Abetz, Napthine's office," Setka said.
"It was just a conspiracy all the way through."
Setka and Reardon had fought hard to get the charges dropped, taking the long-running case to the Supreme Court at one point and finally succeeding on Wednesday, five years after the meeting.
"It's a fantastic result for workers all across this country," Setka said.
"They're trying to take away workers' rights. We're there to fight for workers' rights and that's what we'll continue to do."
During the committal hearing, questions were raised about the Boral executives destroying their original notes about the cafe meeting.
The meeting at North Melbourne's Auction Rooms cafe was called by Boral, which was hoping the union would lift a black ban on its cement deliveries.
The concrete company had become subject of a secondary boycott linked to the union's industrial fight with building giant Grocon, to which Boral supplied.
The CFMEU wanted to appoint its own health and safety representatives at Grocon sites because of safety concerns.
Mr Dalton said Boral had organised the meeting to "do a deal" with the union officials.
During the hearing, defence counsel Neil Clelland QC suggested the meeting began jovially.
"You shook hands, ordered coffee and Mr Setka and Mr Reardon joked about their weight loss challenge," Mr Clelland said.