The powerful construction and maritime union could soon split from its manufacturing, mining and energy divisions under draft laws set to sail through federal parliament.
Legislation to allow members to vote on union demergers outside a three-year window passed the lower house with bipartisan support on Wednesday.
The bill will allow the CFMMEU to be broken up with the powerful militant union riven with dysfunction and chaos after a bruising bust-up between heavyweight officials.
Industrial Relations Minister Christian Porter said the changes would allow members to vote on breaking away from union divisions with a history of breaking the law.
"There are clear examples where the poor conduct of one part of a union is impeding the ability of other law-abiding divisions of the union to work effectively in the interests of their members," he told parliament.
Under existing arrangements, a ballot to split divisions or branches can only be held between two and five years after a merger.
National secretary Michael O'Connor quit the "totally dysfunctional" union last month after Victorian construction boss John Setka waged a campaign to oust him.
A fight over poaching members between divisions played out in court.
Mining and energy boss Tony Maher has flagged plans to leave the super-union after blasting the construction division.
Fault lines in the CFMMEU emerged last year when Mr Setka was charged and later convicted of harassing his wife.
Federal Opposition Leader Anthony Albanese pushed for him to be kicked out of the Labor Party and ACTU secretary Sally McManus called for him to quit for the good of the union movement.
Labor's industrial relations spokesman Tony Burke said the bill made a common sense change to allow withdrawal from amalgamations.
"It's a democratic process involving a ballot of the members," he said.
Greens leader Adam Bandt railed against the bill being rushed through parliament on the same day it was introduced.
"We're in an extraordinary situation where we're being asked to vote and debate on a bill we haven't even had time to read," he said.
In 2019, the CFMMEU had about 69,000 members in construction, 21,000 in mining, 15,000 in manufacturing and 12,000 in maritime.
The maritime and textile unions joined the fold after a merger in March 2018.
