CFMEU boss John Setka has been verbally abused and accosted by a massive group of workers, mostly men without masks, outside the union's headquarters in Melbourne.
The Victorian state secretary tried to address the crowd, who mostly donned high vis jumpers, to address their concerns about mandatory vaccination and passports in construction.
But he could hardly get a word in, and the mob turned violent – pushing and shoving – as he attempted to retreat within the Carlton headquarters.
As he tried to leave, members of the group lobbed bottles and trays at him and other union representatives.
Mr Setka could be seen holding his hands up as the group surged forward near the entrance and appeared to break out in a scuffle.
Earlier, Mr Setka said : "Please let me have a say".
"I have never… said I support mandatory vaccination," he said through a loudspeaker.
"I will address the concerns of CFMEU members," he added. "Are you going to let me talk or shout over the top of me."
The group shouted "F**k the jab" at Mr Setka. They also shouted: "Stand up or stand down".
Mr Setka said: "I can't even hear myself think.
"I've done jail for this union. I've stood on picket lines for this union," he said. "We have tried to keep CFMEU workers (working) since April last year.
"I did not mandate vaccinations."
CW: Violent footage.— Eden Gillespie (@edengillespie) September 20, 2021
Construction workers protesting mandatory vaccinations clash with union officials and Victorian State Secretary John Setka outside the CFMEU office. pic.twitter.com/uVKTuIzQ8r