Scott Morrison says he's never been a fan of the NSW anti-corruption watchdog and calls to replicate it on a federal level must not be driven by the "latest thought-bubble".
The prime minister has doubled down on his criticisms of the NSW Independent Commission Against Corruption and says he doesn't care if high-profile legal minds disagree with him.
"I have serious criticisms of the NSW ICAC model," he said on Tuesday.
"I've never been a fan of how it's conducted itself.
"And I don't care if barristers and lawyers and others up there in Macquarie Street - not in the (NSW) parliament but in the barristers' chambers - disagree with me."
Mr Morrison has repeatedly criticised the NSW ICAC, referring to it as a "kangaroo court", when he was under pressure to introduce a federal integrity commission.
Last week retiring ICAC Commissioner Stephen Rushton responded, telling a NSW parliamentary review those calling the commission a kangaroo court were "buffoons", saying the comments could undermine public confidence in the ICAC's work.
Appearing with NSW Premier Dominic Perrottet on the campaign trail on Tuesday, Mr Morrison said he stood by his comments.
"I don't believe the NSW ICAC is a model we should follow at the federal level," he said.
"I've seen it come and destroy people's reputations and careers before it has even made a finding and I don't think that's good process.
"The design of it has to be right. It's not just about having any integrity commission, one that is driven by populism, one that has just been driven by the latest thought-bubble."
Mr Perrottet conceded he and the prime minister disagreed.
"What we both agree on is that there should be integrity agencies in place that ensure the best standards in public life," the premier said.
"I agree with the prime minister (in that) it's not a one-size-fits-all approach."
The ICAC played a pivotal role in maintaining high standards of public office in NSW, he said.
"We have people in jail today because of their behaviour and the corruption that occurred in relation to - take (former Labor MP) Eddie Obeid for example - the previous government, which corruptly used taxpayer dollars for personal benefit," Mr Perrottet said.
"As premier of this state, whether it's politicians or whether it's the public service, I expect the highest standards of integrity."
