The Prime Minister, who promised to introduce legislation almost three years ago, has been happy to let it sit on the backburner during a succession of crises including the "Black Summer" fires and the pandemic.

This has been despite a string of controversies involving his government which, if they had occurred in NSW, would almost certainly have resulted in investigations by the NSW ICAC.

ICAC's decision to investigate Ms Berejiklian prompted her decision to quit politics.

The reaction to this has been dramatic, with senior Coalition figures, including Barnaby Joyce, coming out swinging. "The process of ICAC is lauded by people who want greater power for minority groups against the wishes of the majority," he said on Monday. "This is not the great sort of righteous process, it's a little bit like the Spanish Inquisition."

Amanda Stoker, who is charged with helping to prepare legislation for the federal integrity watchdog, also invoked the "I" word in regard to the NSW ICAC.

"Its broad sweeping powers of inquisition and compulsion have seen lives destroyed over trivialities [and] careers ended over investigations that have gone nowhere," she said.

That seems a tad pre-emptive, given Ms Berejiklian has yet to testify. Surely it is a mistake to intimate the matters in question are trivialities and that the investigation will go nowhere even before the process has begun?

Mr Morrison, meanwhile, has done nothing to hide his disdain for the NSW body, its wide-ranging powers, and the fact much of its work is conducted in the full glare of public scrutiny.

"It's certainly not a model that we'd ever consider at a federal level," he said.

"You've got to have processes that assume people are innocent before they are thought to be guilty".

While those concerns have merit, and the failed attempt by independent MP Helen Haines to establish a federal body included a provision for early hearings to be in private, the PM's real concern seems to be an anti-corruption body could venture into areas some would prefer left unscrutinised.

The government's original proposal, outlined by the then attorney-general Christian Porter in 2018, was slammed as a toothless tiger, with former NSW ICAC commissioner David Ipp describing it as "the kind of integrity commission you'd want to have when you don't want an integrity commission". Mr Ipp also said the NSW body only held public hearings when they were in the public interest.

The shadow attorney-general, Mark Dreyfus, who has been pushing the government hard over the integrity body delay, believes it would be possible to include protections against people being unjustly smeared.

His boss, Anthony Albanese, who has so far failed to hold the government to account over "sports rorts", the car park rorts, secret donations to Christian Porter and concerns about allegedly forged documents circulated by Angus Taylor's office, is also critical of the Morrison model.

This is despite failing to put forward a detailed outline of what a Labor government-initiated integrity body would look like, who it would be answerable to, the exact scope of its powers and when it might be up and running.

Given an election is likely to be held within the next six months, these are issues the opposition is under just as much pressure to address as the government.