Integrity experts have backed a public model of a federal corruption watchdog as the prime minister ditches his promise to establish one.
Scott Morrison said a federal watchdog hosting public hearings would become a "kangaroo court" that would tarnish people's reputations.
But top silks say a federal model would be ineffective without public examinations with Mr Morrison's government's proposed model barring politicians from being subject to public hearings.
The Centre for Public Integrity on Friday pointed to the fact the NSW Independent Commission Against Corruption (ICAC) had only held 42 public inquiries despite nearly 1,000 private examinations between 2012 and 2020.
"Sunlight is the best disinfectant. Public hearings expose corruption, and many investigations would not be successful without them," director Geoffrey Watson said.
"Far from overuse, NSW ICAC holds public hearings only in a fraction of its investigations when it is in the public interest to do so."
Federal government ministers blasted the NSW model last year after the over grants paid to a club in Daryl Maguire's electorate, who she was in a relationship with at the time.
Previous NSW ICAC investigations have led to the imprisonment of former NSW Labor ministers Eddie Obeid and Ian Macdonald.
Mr Morrison promised to introduce a federal anti-corruption body during this term of parliament ahead of the 2019 election.
But in a proposal established by the Coalition in 2021, the public sector commission would not be able to host public hearings, investigate tip-offs from the public or issue public findings.
The prime minister's rationale was relentless public scrutiny that Labor wanted in the model would eventuate into what he described as a "kangaroo court".
Labor promised to introduce a stronger federal model if elected in May, with politicians to be subject to public hearings and the agency able to act on tip-offs.
"I am not going to introduce a kangaroo court," Mr Morrison told reporters on Thursday.
"What I am concerned about is the circus that Labor would want to put in place with an integrity commission."
Earlier in the week, he wouldn't commit to trying to establish one if he wins the upcoming election.
The Centre for Public Integrity has pointed to previous comments from former executives at state corruption watchdogs.
Former NSW ICAC Commissioner David Ipp said the state watchdog's work cannot be done without public hearings.
Former Independent Broad-based Anti-corruption Commission head Stephen O'Bryan has said public hearings were vital and an "invaluable tool" for highlighting corruption and warning against it.
Despite the prime minister's insistence against a federal ICAC, Liberal frontbenchers Stuart Robert and Simon Birmingham on Friday contradicted the prime minister's refusal to push forward with a proposal.
"We will come back again and we will seek, through a bipartisan level, to get that going," Mr Robert told Nine's Today program.
Mr Birmingham told Sky News that if the Coalition was re-elected, it would maintain a mandate to implement its proposed model, despite the stark opposition against it.
"We're not going to legislate for the type of reputation-destroying, star chamber model we've seen in NSW," he said.
