Speaking to reporters in Brisbane on Saturday, Attorney-General and Industrial Relations Minister Christian Porter said the announcement was meant to help "good, hard-working members of unions (who) get stuck inside a union that may not be working in their best interest".

"We have seen some terrible behaviour from parts of the CFMEU yet there are other parts of the CFMEU who work hard on behalf of their members and would appear they want to leave that union and they should be given that opportunity," he said.

Industrial relations law currently prevents one part of a registered organisation leaving five years after merging.

The government's bill, to be introduced next week, would allow the Fair Work Commission to approve a vote for a de-merger after that period, if it considers it is appropriate based on specified considerations.

Mr Porter said this would allow dissatisfied divisions of the CFMEU to apply for a ballot for their members to decide whether to break away and then take their members with them to form their own, standalone union.

The Fair Work Commission would have to consider whether the merged organisation has a record of not meeting workplace laws or of not meeting standards for registered organisations.

It would also have to look at the ability of the new organisation to protect its members' economic and social interests.

Victorian CFMEU secretary John Sekta was expelled from the Labor party in 2019 over alleged comments about family violence campaigner Rosie Batty. Last year, he was also found guilty of using a carriage service to harrass his wife.

The government also plans to introduce a new omnibus industrial relations law next week.

Mr Porter said on Saturday the bill would address issues like allowing an employer to offer an employee extra hours at ordinary wage rates. Currently, the employer must offer a higher wage or not offer the extra hours.

Australian Associated Press