The CFMEU and more than a dozen officials have been fined almost $1 million over multiple industrial breaches at construction sites across Adelaide.
The Federal Court on Friday handed down several judgments against the CFMEU over offences committed at 10 construction sites, including Adelaide Oval, Flinders University and Adelaide Convention Centre, between October 2013 and May 2014.
The union was fined a total of $856,000, while 15 of its officials shared in fines of more than $81,000.
Multiple breaches related to officials entering sites without providing notice, refusing to leave when asked and threatening to bring work to a halt.
"The CFMEU's dismal record means that deterrence must be a particularly important consideration in the penalties imposed on it," Judge Richard White said in one of the judgments.
The bulk of the offences were committed at sites owned by builder Lend Lease over the course of two months in late 2013.
Judge White said he was satisfied the union had engaged in a concerted campaign at Lend Lease sites "in deliberate defiance" of the Fair Work Act requirements.
The judge said the CFMEU had a "regrettable record of indifference to, or defiance of, the law" which called for strict penalties to be imposed.
"Substantial penalties have been imposed on the CFMEU in the past without deterring it from unlawful conduct," he said in one of the judgments.
"That suggests that even more severe penalties should be imposed now."