Attorney-General Christian Porter has hit back at claims the government's union-busting legislation will be used to deregister unions and disqualify officials over "paperwork" breaches, detailing the CFMMEU's criminal rap sheet and record of intimidation on work sites.

Mr Porter said in Parliament on Monday Labor's claim the legislation would allow unions to be dismantled over "non-serious matters" was "just absolutely and utterly incorrect".

Attorney-General Christian Porter is seeking crossbench support for the Ensuring Integrity Bill. Credit:Alex Ellinghausen

He detailed the Construction, Forestry, Maritime, Mining and Energy Union (CFMMEU) and its organisers' convictions, including for drug dealing, intimidating a female police officer and bullying non-union workers; along with the Australian Workers' Union's artificial inflation of member numbers.

"What about the apprentice who gets bullied and lied to and intimidated and he can't go to work because he doesn't want to join a union?" Mr Porter said.