The AFL has vowed to stand behind its head of umpires, Stephen McBurney, following threats from the CFMEU's Victorian leader.
Construction union boss John Setka addressed media today, warning of potential disruptions to the league's construction projects unless McBurney, the former Australian Building and Construction Commissioner, was dismissed.
McBurney previously launched legal action against the union multiple times, resulting in fines worth millions.
McBurney was appointed to his AFL role in April and has umpired more than 400 games in the league.
The AFL today released a statement supporting McBurney.
'All projects the AFL contributes to are designed to provide better training venues for AFL and AFLW players, gender friendly facilities and change rooms at community football clubs and to create a more welcoming footy environment for families who make up many of the 1.2 million club members and the many more millions of fans who attend games," the statement said.
"We are hopeful any intended action does not impact players, supporters or the wider community who benefit from upgrades to local clubrooms and our stadiums.
"Steve McBurney umpired 401 games, including four AFL grand finals, he has been a long-time mentor to umpires at every level and has done an outstanding job since returning to the AFL to take up the role of Head of Officiating."
The union boss confirmed members would not strike or simply stop work but would instead only work basic hours, meaning no weekends, which could lead to time delays.
Setka said the AFL needed to cooperate with the union and ultimately sack McBurney, who he described as a "sell-out".
"For him to go to the AFL, which is Australia's number one sport, to be in charge of the umpires, it's an absolute travesty," he said.
"Why go to the AFL and the umpires already have it hard enough as it, let alone to be getting orders off someone like Mcurney who is pretty undemocratic and should belong in North Korea if I am being honest."