Last week the Liberals' industrial relations spokesman Andrew Wall used parliamentary privilege to say "numerous criminal and civil charges" against the union in recent years raised "serious questions around whether or not the union is fit to have such an influence over public policy".

It came after the CFMEU's ACT branch secretary Jason O'Mara was charged the week before and the Australian Competition and Consumer Commission alleging cartel conduct.

Mr O'Mara is accused of attempting to "induce suppliers of steel-fixing services and scaffolding services to reach cartel contracts, arrangements or understandings containing cartel provisions in relation to services provided to builders in the ACT in 2012 to 2013".

Despite the serious charges, on Saturday, August 18, the party carried a unanimous urgency motion at its annual conference in support of Mr O'Mara. It was moved by Mr O'Mara's deputy, CFMEU ACT assistant secretary Zach Smith, and seconded by national Community and Public Sector Union president Alistair Waters.

"ACT Labor condemns the ongoing criminalising of union organising by the anti-worker Turnbull federal government," the motion said.

"ACT Labor stands in solidarity with Jason O’Mara who has been baselessly charged with a criminal offence for doing nothing more than negotiating better pay and conditions for construction workers. Union organising is not a crime.

"We call on federal Labor to end the politicisation of federal law enforcement agencies and regulators who under the Turnbull government are pursuing a relentless anti-union agenda."

Mr O'Mara could face up to 10 years jail if the charges are successful, and the union faces up to $10 million in fines or 10 per cent of its turnover.

The party's platform was also changed to further emphasise its reliance on the union movement at the conference. Phrases added to the party's platform included recognising the party was founded by the union movement and "remains the political wing of the union movement".