The head of the nation’s biggest construction union is set to be hurled before a court as the regulator in charge of industrial relations in the building sector pursues action against a number of union officials over their conduct involving a blockade at a $1.2 billion hospital project in Perth.

On Thursday, Fair Work Building and Construction (FWBC) announced it had launched Federal Court proceedings against Construction, Forestry, Mining and Energy Union (CFMEU) National Secretary Dave Noonan as well as State Secretary Mick Buchan, Assistant State Secretary Joseph McDonald and organiser Tawa Harris over alleged breaches of the Fair Work Act 2009 in relation to a blockade of a concrete pour which was scheduled to take place on the site of the New Children’s Hospital in Perth on July 18 last year.

The union itself has also been named in the action along with its Western Australian state chapter.

In a statement, FWBC alleged the officials were aware disruption to the pour would impact project milestones and expose head contractor John Holland to financial detriment, and that the action was taken in a bid to force the company to agree to enterprise agreement demands which included a ‘whole of site’ agreement applying common terms to all workers on site including non-John Holland personnel.

It says the union posted Facebook notices and issued fliers the day before the action.

Around 600 workers allegedly gathered the next day and blocked the main site entrance before moving to a nearby park after it became clear the pour would not take place.

Addressing the crowed at the park, Buchan allegedly said the workers and union had sent a message about their ability to ‘pull the numbers whenever we f***ing need them’ and would do whatever it needed to do.

“The one important thing that has happened here today is we send a clear message to everyone around here that’s here today that we can pull the numbers whenever we f***ing need them and we’ll do whatever we need to do,” he allegedly said words to the effect of.

McDonald, meanwhile allegedly told the crowd that the workers would not go back to work on that day and said words to the effect that ‘we are the union and we called the shots today’.

FWBC Director Nigel Hadgkiss said his agency is committed to upholding workplace laws on Australian building and construction sites.

Maximum penalties are $10,200 for each breach of the law for individuals and $51,000 per breach for unions.

Meanwhile, FWBC has also commenced proceedings in the Federal Court of Australia against CFMEU organiser Joseph Myles for allegedly threatening ‘war’ and organising a blockade on the $4.102 billion Regional Rail Link project in Victoria over the head contractor’s refusal to employ a union delegate.