There were loud assertions from unions at May Day rallies over the weekend as they pledged to maintain their various fights.

A building union official told the rally in Sydney that he would rather go to jail than “give up” a fellow worker under interrogation.

CFMEU delegate Dennis McNamara said the Federal Government’s bill to resurrect the Australian Building and Construction Commission (ABCC) was “disgraceful”, and contained extraordinary coercive powers.

He said the revived Commission would force building workers to attend interviews, compel them to speak, and even threaten jail time for those who refuse.

The ABCC revival bill has been rejected by the Senate twice.

Mr Macnarama said the coercive powers would deny building workers the right to silence, something they would have under the normal legal system.

“It means that as a building worker I don't have that right to silence,” he said.

“I could leave here today and go and murder someone, or go down the road and sell ice to a 14-year-old kid, and when I am interrogated [I'd] have the right to silence under our law and I can have a legal representative of my choice,” he said.

“But because I'm a building worker and I work in the construction industry, I'm denied that right under this bill, and that's shameful.”

He said that if called upon, he would not tell the ABCC anything.

“What I face if I don't speak up, is six months jail,” he said.

“I don't want to go to jail, nobody wants to go to jail.

“My children who are up here with me, they don't want to come and visit me in jail because I won't 'give up' a fellow worker.

“But I won't do it. And if I have to, I will go to jail for it. And so will many others.”