The government has announced it will ban “corrupting benefits” being paid between employers and unions, and allow courts to disqualify union leaders to crack down on unlawful conduct.

The employment minister, Michaelia Cash, made the announcement at the National Press Club on Friday, confirming the government will adopt the “overwhelming majority” of recommendations from the trade union royal commission.

But Cash refused to say whether it will adoptProductivity Commission recommendations to introduce a new form of contract to vary award conditions or give economists more input in the minimum wage.

Cash said the government would give the courts power to disqualify union officials where they have been repeatedly found to have breached workplace laws, as recommended by the royal commission.

“Whilst I have no doubt that this critical reform will be opposed by Labor, it is not in any way controversial,” she said, arguing that company directors and drivers are banned for repeated offences. “The same principle should apply in the workplace.”

Construction Forestry Mining Energy Union construction national secretary, Dave Noonan, told Guardian Australia “the thing that Senator Cash can’t comprehend is that workers choose their elected officials, courts and politicians don’t and shouldn’t”.

“Unions are democratic organisations. Union officials should be elected by members,” he said.

Noonan also noted the government had not adopted royal commissioner Dyson Heydon’s “more bizarre recommendations” including that parliament should be able to ban construction officials and said it showed how “extreme and ideological” the royal commission was.

Cash said the Turnbull government would also adopt the recommendations to ban secret payments between unions and employers, known as corrupting benefits.

She referred to the Cleanevent case study, in which the royal commission found that the cleaning company paid the Australian Workers Union $25,000 a year to continue an outdated collective agreement that resulted in workers losing penalty rates worth more than $1m.

“It is an obvious conflict of interest for money or reward to be changing hands between an employer and a union at the same time that they are negotiating a workplace agreement,” said Cash.

“Workers deserve to know that the union rep cannot go into the boss’s office and do a dodgy deal behind their backs to cut their wages. When money changes hands in this way between a union and a company, there is always a loser and that is the worker.”

When asked if this would apply to payments from unions to employers, Cash replied “this is about both parties to any transaction, not one particular side of the transaction”.

The Shop, Distributive and Allied Employees’ Association has come under fire for paying major employers millions of dollars in payments as “commission” for the employers deducting union fees from members’ pay packets.

Cash said the law would not affect “legitimate payments”. This suggests payments for union-provided training or commissions from insurance may still be legal, although the government would require that they be disclosed.

Noonan said: “If the government is concerned about corrupting payments – I suggest they review CFMEU’s catalogue of concern that shows Liberal links to developer party slush funds.”

The shadow employment minister, Brendan O’Connor, said if elected Labor would set an objective test for casual work, a move which could force employers to hire workers as permanent employees.

O’Connor said Australia faces record levels of underemployment, as people want more work but can’t find it. “Increasingly, the oxymoronic term permanent casual is being used by employers to describe their employees,” he said.

“That is why Labor will examine the definition of casual work by setting an objective test for determining when a worker is a casual and when he or she is not.”

Cash was asked about Productivity Commission recommendations including a new form of contract, the “enterprise contract”, which could undercut award wages and be presented to new workers on a take-it or leave-it basis.

Cash said the government would respond “in due course”, despite the fact there are just 15 days left to run in the election. She listed the governments’ other industrial relations policies, including a tougher building industry regulator and increased penalties for worker exploitation.

O’Connor criticised what he said was the government’s failure to outline its full industrial relations policy. “There was no actual response to any of the recommendations of the Productivity Commission in that,” he said.

“The fact that there’s been no response at all again underlines how incompetent and lazy the government is … we’re two weeks away from an election.

“These matters should have been, if they’re so serious, they should have been matters that were reflected in bills proposed to the parliament for consideration by the parliament this term.”

O’Connor signalled Labor was considering a more “flexible way to negotiate with small businesses” but said any changes would be fair to employees.

Other royal commission recommendations accepted by the government include increased whistleblower protection, criminal penalties for dishonest breach of union leaders’ duties, and preventing unions paying their officials’ fines.