A panel of legal experts has released a design for a national integrity commission with far-reaching powers in a move that will increase pressure on the Turnbull government to declare a position on the proposed anti-corruption body.

The Australia Institute’s panel of former judges has called for a body with the power to hold public hearings and broad jurisdiction to investigate all forms of corruption, not just criminal offences.

In March, the attorney general, Christian Porter, told Guardian Australia the government was considering “detailed models” for an anti-corruption body, including by combining some existing organisations.

The Turnbull government has not ruled out creating a federal Independent Commission Against Corruption, as Labor proposed in January, and Porter has held consultations to address concerns in the Coalition including the possible harms to witnesses’ reputations from such an entity.

On Monday, the former Victorian court of appeal judge Stephen Charles will launch the proposal in Canberra for an agency with jurisdiction to investigate “any conduct of any person that affects the impartial exercise of public office”.

Its reach would not be limited to public officials or criminal conduct, and it would have powers to investigate cases as diverse as Brian Burke’s lobbying activities and the Victorian mafia’s alleged political connections. It should also be able to investigate the federal judiciary, the panel recommended.

It said the national integrity commission should be able to hold public hearings “if the commissioners consider it would make the investigation more effective and be in the public interest”.

That test would not require counsel assisting the commission to demonstrate exceptional circumstances or reasonable grounds to hold a public hearing.

“All the state anti-corruption commissioners think they need and should have powers to hold public hearings,” Charles told Guardian Australia.

“That’s the only way you’re going to expose corruption properly, make the public understand the nature of corruption and the harm it does to the community.”

In a briefing paper, the panel noted that the former inspector of the NSW Icac, David Levine, had warned that public hearings could cause “the undeserved trashing of reputations” but noted that they had been supported by the NSW parliament, several high court judges and state anti-corruption bodies.

It said public hearings increased public trust, encouraged witnesses to come forward with new evidence, generated new leads and deterred others from engaging in corruption.

Public hearings had been critical to the NSW Icac’s investigations of leases and mining licences that resulted in the prosecution of Eddie Obeid and Ian Macdonald for misconduct, the panel said.

The national integrity commission would have all the powers of a royal commission but would not be a judicial body, although it could refer cases to the director of public prosecutions if there was evidence of criminal conduct.

The blueprint calls for the independent integrity commissioner to be nominated by a bipartisan committee.

Charles said the national integrity committee had “completed the next stage in designing an effective federal anti-corruption body”.

“It’s now time to get on with the job of investigating and exposing corruption to restore public trust in government,” he said.

The Australia Institute’s executive director, Ben Oquist, said a national anti-corruption body was “incredibly popular with the Australian public, and for good reason”.

“There is now a roadmap for what we hope will be bipartisan progress,” he said.

Charles said “obviously some politicians will have a very strong view that there should be no public hearings”.

He said the panel had kept “political realities” in mind but “we’ve been doing our best producing the model most likely to be effective”.

The expert panel included the former president of the Queensland court of appeal Margaret McMurdo, former commissioner of the NSW Icac David Ipp, former Victorian court of appeal justice David Harper, and former NSW court of appeal justices Anthony Whealy and Paul Stein.