The federal government confirmed the wide-ranging judicial inquiry on Sunday, saying it would examine allegations of impropriety at the health services, construction and Australian workers unions.

North East Border Trade and Labour secretary Chip Eling echoed Labor Opposition Leader Bill Shorten’s comments that police should be running the investigation.

“It’s a political witch-hunt; there are a number of other bodies available, not least the Crime Commission that could lead an investigation,” he said.

“If there are laws broken, the police can investigate that.”

Mr Eling defended Border unions, saying he wasn’t aware of any corruption.

“I’ve never come across a single example of corruption; I’ve never offered a bribe or been offered one,” he said.

“If I was aware of it, I’d inform the relevant authorities.”

But Mr Eling conceded there were “probably grounds for an investigation”, just not a royal commission.

“I’m not saying it doesn’t happen,” he said.

But he dismissed Liberal Party claims the corruption was ingrained, saying there were only five or six union officials out of thousands who had been implicated.

Mr Eling also blasted what he called a “massive double standard”, with no investigation into those Liberal politicians alleged to have been rorting the public purse.

“I don’t hear any calls for a royal commission into that,” he said.

He also questioned the estimated $100 million cost against the government’s refusal to bail out Toyota and Shepparton-based SPC.

“They’ve got $100 million to spend on a political witch-hunt and they haven’t got $25 million to spend on a part of regional Australia that’s completely devastated,” he said.

Labor and the Greens have both rejected the need for a royal commission, saying a joint police taskforce would be cheaper, quicker and more effective.

The royal commission will be headed by former High Court judge Dyson Heydon and has been given a suggested reporting date of the end of the year.