The federal government says it's prepared to consider de-registering the Victorian branch of the Construction, Forestry, Mining and Energy Union.

It follows allegations of serious criminal infiltration of major building sites across Victoria, New South Wales, Queensland and South Australia.

The controversial head of the Victorian branch, John Setka, abruptly resigned after the allegations were put to him by journalists at Sixty Minutes and the Chnnel Nine papers.

Guest: Jim Chalmers, Treasurer