Labor leader Bill Shorten distanced himself from the newly minted ACTU leader Sally McManus after the union boss condoned breaking laws she sees as "unjust."

Ms McManus was endorsed as the ACTU's first female secretary on Wednesday. In her first major televised interview, Ms McManus was asked if she would distance herself from the CFMEU union, which its critics describe as militant.

"There's no way we'll be doing that," Ms McManus told the ABC's 730 program.

"I'll tell you this, the CFMEU, when they've been fined for taking industrial action... it might be illegal industrial action according to our current laws but our current laws are wrong."