Prime Minister Scott Morrison has vowed to tackle "union thugs" with a renewed push to enact the government's union-busting bill after last week's shock Senate defeat, talking up his reforms passed after the banking royal commission in comments directed at One Nation.

"We believe that union thugs should not go on to building sites and threaten people or in any area of the workplace," Mr Morrison told reporters in Canberra on Monday.

Scott Morrison says he acted on banking misconduct and it's time to tackle union thugs. Credit:Alex Ellinghausen

He said law-breaking union officials should face expulsion for intimidatory behaviour.

"I put laws in place to do that to bankers," Mr Morrison said. "It should be in place to do that to union thugs too."