'Serious threat': The controversial laws targeting the CFMEU, explained

An angry construction union hit out at being forced into administration following alleged corruption after Labor secured the Coalition's vote to pass the law — a deal the Greens have also criticised.

An external takeover of the construction union and its branches will be cemented after Labor secured the numbers to pass laws to appoint an administrator. Source: AAP / Jono Searle

Key Points

• Legislation giving the minister power to appoint an administrator passed the Senate on Monday.
• The Opposition agreed to pass the bill after securing several amendments.
• The union criticised the law, saying it stripped members of the right to a fair process.

The fate of the Construction, Forestry and Maritime Employees Union (CFMEU) has been sealed after the Coalition gave Labor the green light to pass laws neutering the construction union's resistance to external administration.

The Greens have labelled the legislation a "serious threat to the rule of law", but the federal government "completely" disagrees with that assessment.

The move comes after the CFMEU was thrust into the spotlight in July over allegations of corruption and links to organised crime figures. The union has been critical and resistant to a federal government push to place it under administration.

What would the new laws do?

The legislation would give the relevant minister power to appoint an administrator.

The Opposition agreed to pass the bill after securing several amendments, including a three-year minimum administration period for the union and its branches that only the administrator could end early.

The administration period can last up to five years under the law and officials found guilty of crimes would be banned for life and unable to become bargaining agents at other registered organisations without holding a fit-and-proper-person certificate.

Those who attempt to frustrate or obstruct the process could face hefty fines and two years in prison.

The administrator has assured the Opposition that the union would not spend money on political campaigns or donate during the takeover.

Workplace Relations Minister Murray Watt said an administration scheme would be in place "over the next week".

The union could challenge the bill in court.

What has the reaction been?

The union criticised the law, saying it stripped members of the right to a fair process.

Criminal allegations were taken seriously and people had been stood down pending legal proceedings but they remained untested in court, CFMEU national secretary Zach Smith said.

"Until allegations have been tested by the legal system, people and organisations are entitled to a fair process," he said.

Greens leader Adam Bandt said if the Opposition won the next federal election, they could bring former prime minister Tony Abbott in to administer the union.

"What Labor and the anti-worker Liberals have done is rush through legislation that is an unprecedented attack on the rule of law," he told reporters in Canberra.

But Watt disagreed.

"I would completely disagree that this is an attack on construction workers, quite the opposite," he told ABC News on Tuesday.

"Construction workers deserve to have a strong and effective union, but it's got to be a clean union."

Business and building groups have also welcomed the move.

What happens next?

The legislation passed the Senate on Monday and is set to be ticked off in the lower house as early as Tuesday.