The coalition government will revive plans to make it easier to deregister unions and disqualify law-breaking officials, with industrial relations emerging as a key election battleground.
Industrial Relations Minister Kelly O'Dwyer has boosted employer groups' hopes that shelved legislation will be back on the agenda.
The draft laws would subject union mergers - like the amalgamation in which the maritime and textiles unions joined the CFMMEU earlier in the year - to a public interest test.
The bar for deregistering unions would be lower, while courts could disqualify officials if they deemed they were not "fit and proper" people.
Crossbench senators stopped the bill in its tracks in March, forcing the government to put its plans on hold.
Ms O'Dwyer on Tuesday repeated calls for Labor leader Bill Shorten to sever political and financial ties with the CFMMEU.
"Mr Shorten and Labor can do the responsible thing now and protect workers and small businesses from workplace bullying and stand-over tactics, instead of continuing to protect union thugs and their criminal associates," she said.
Prime Minister Scott Morrison hasn't backed away from a threat to deregister the controversial union after voicing his disgust with a Victorian official using his children to campaign against the building industry watchdog.
CFMMEU Victorian official John Setka posted a picture of his children holding a sign saying 'Go get f*#*ed' with the caption "Leave our dads alone and go catch the real criminals you cowards".
He later deleted the tweet, admitting he shouldn't have included his kids and saying he was emotional on Father's Day after a tough year on his family.
Mr Morrison said thugs were running unions and Mr Shorten, but the Labor leader said the attacks on the CFMMEU were a distraction.
"The government is talking about the CFMEU and unions because they've run out of anything to talk about with everyday Australians," Mr Shorten told reporters.
The union's national construction secretary Dave Noonan said it would vigorously resist any deregistration attempts.
"It's disappointing but not surprising that a broken and divided government is resurrecting the CFMEU bogeyman in an attempt to frighten voters," Mr Noonan said.
He said the prime minister had nothing to say about the alleged criminal behaviour of banks, along with stagnant wages and the death toll in the construction industry.
