Former police minister Mike Gallacher could not hide his glee in Parliament as the Government passed legislation to overhaul New South Wales' corruption watchdog and effectively sack its commissioner.

Key points: Gallacher attacks ICAC in Parliament

Gallacher attacks ICAC in Parliament Claims watchdog is law unto itself

Claims watchdog is law unto itself He was named in 2014 investigation

Mr Gallacher launched a blistering attack on the Independent Commission Against Corruption, claiming it "had a pre-determined outcome" for every inquiry it held.

Mr Gallacher is no stranger to the ICAC — he resigned as a minister and moved to the crossbench in 2014 after he was publicly named in an inquiry into corruption in Liberal Party ranks.

He made the claim on Wednesday during a debate about the bill that would overhaul the ICAC and force commissioner Megan Latham to reapply for her own position.

The bill, unveiled on Tuesday, would restructure the ICAC so it has three commissioners, with two having to agree before a public inquiry can be held.

Labor has accused the Government of using the restructure of the corruption watchdog to effectively sack Ms Latham for investigating the Liberal Party.

Mr Gallacher said the ICAC believed it had "no legal barriers".

"Is this what justice and honesty looks like in NSW in 2016? We now understand the culture of this discredited outfit," he said.

"Well I've got news for you commissioner and it's all bad.

"Organisations blinded by their own righteousness who will do anything within their power to obtain the evidence it needs to set in concrete the case it is seeking to prove is a breeding ground for noble cause corruption."

He said the ICAC recklessly destroyed peoples' reputations and denied them the right to clear their name even if they could not be successfully prosecuted.

"If ICAC cannot prosecute you, they persecute you," he said.

Mr Gallacher could not hide his feelings at the prospect of Ms Latham losing her job.

"I'm often asked as being forced to resign as leader and minister of this house on the 2nd of May 2014 why I would want to stay in Parliament," he said.

"The reason is simple, it's an honour to be here ... and besides that I like my job.

"And despite the occasional challenges, some days just come along where it just cannot get any better, and let me tell you that's exactly how I feel today."

ICAC Commissioner Megan Latham will have to reapply for her job. ( AAP: Dean Lewins )

ICAC changes slammed

Two former commissioners have slammed the Baird Government's legislation.

Former commissioner David Ipp said it appeared designed to get rid of Ms Latham because she had been too independent.

"I think it is a scandalous move," he told the ABC.

Another former ICAC chief, Anthony Whealy, said it would effectively sack the commissioner in the middle of her tenure.

"It's absolutely stunning that this has happened and there seems to be no justification for it whatsoever," he told the ABC.

"I think it's very wrong and very harmful and should be very damaging to the Baird Government.

"It's outrageous and shameful. This is a means of dampening down the ICAC and removing its powers."