Treasurer Joe Hockey says a Senate inquiry hearing into the Abbott government’s commission of audit is just a Labor/Greens stunt.

The chair of the commission, former Business Council chief Tony Shepherd, will front the hearing in Canberra on Wednesday to answer questions about his work ahead of an interim report due to be delivered to Mr Hockey in the coming weeks.

But Mr Hockey says it’s a show trial.

“This is just a new year stunt from the Greens and the Labor Party, and it reflects the lack of maturity from the opposition,” the treasurer told ABC radio on Wednesday.

Mr Hockey says the commission’s work will “eventually” be made public, but its recommendations need to be fully considered by the government before that happens.

“We’ve given them the brief, we’ve given them the resources – let them get on with doing the job.”

He dismissed suggestions that Mr Shepherd or other commissioners may have conflicts of interest as “novel”.

The commission of audit – similar to that undertaken by the Howard government in 1996 – was set up to find savings across the public service and also consider the privatisation of public assets.

Opposition Leader Bill Shorten said Australians had a right to know what would be cut from the budget as a result of the audit.

“That’s what these Senate hearings are all about – what is the truth?” Mr Shorten told ABC radio.

He said the commission would have already settled some of its recommendations, given its interim report was due soon.

“The commissioners, if they don’t provide answers to questions, have clearly been gagged by the government.”

He accused the government of trying to keep any cuts secret until at least after next month’s by-election in former prime minister Kevin Rudd’s seat of Griffith.