The Labor caucus on Tuesday reaffirmed its opposition to the Ensuring Integrity Bill which will be debated in the lower house on Wednesday.

But the Morrison government will be able to use its majority to pass the bill in the lower house, setting it up for a showdown in the Senate.

The Greens also oppose the bill, forcing the coalition to negotiate with crossbenchers.

Industrial Relations Minister Christian Porter said Labor was putting its union mates - such as the construction union CFMMEU - ahead of the interests of all Australians.

"Anthony Albanese has put the $1 million a year Labor receives from the CFMMEU ahead of the needs of all Australians and the Australian economy," Mr Porter said.

He said the opposition's decision to vote against the bill was an endorsement of militant unions' law-breaking.

"It is Australian taxpayers who ultimately bear the cost of Labor's refusal to deal with law-breakers within their union ranks," Mr Porter said.

The Australian Chamber of Commerce and Industry said it was appropriate the government called time on union officials with deep pockets, arrogant attitudes, and combative lawyers "thumbing their nose" at industrial laws.

"Unions and registered employer organisations enjoy significant rights and privileges in Australia and they need to meet proper standards of conduct and accountability," ACCI boss James Pearson said.

The laws are part of the government's response to recommendations of the unions royal commission headed by former judge Dyson Heydon.

The Australian Council of Trade Unions last week released research it commissioned which found the legislation could break Australia's international obligations.

"This extreme new law would align Australia with authoritarian, undemocratic countries," ACTU president Michele O'Neil said.

Australian Associated Press