Crossbench MP to refer Perrottet to police

NSW Premier Dominic Perrottett will be referred to police after a minor party questioned whether he breached the law by not declaring his Nazi costume incident when he joined the Liberal party.

Mr Perrottet on Sunday sought to draw a line under the controversy and again apologised for his actions, after admitting on Thursday he wore a Nazi costume to his 21st birthday party.

NSW Shooters, Fishers and Farmers party leader Robert Borsak wants to know if Mr Perrottet broke the Oaths Act by declaring on a Liberal Party preselection document around 2010 that he had nothing to disclose that could embarrass the party.

It's a gambit by Mr Borsak because it is not known if Mr Perrottet failed to declare the now-controversial incident because his preselection document remains confidential.

"It's long past time that he be held to account, he is not above the law," Mr Borsak said in a statement on Sunday.

Mr Perrottet's office said Mr Borsak's move was a "stunt".

"The premier has apologised for making a terrible mistake at his 21st birthday and this is nothing more than a stunt to distract from the issues plaguing SFF," a spokesperson said.

In September, Mr Borsak suggested independent MP and former party member Helen Dalton should be "clocked".

This prompted two of his MPs to quit after he refused to apologise or resign over the comments. The party has two upper house members, including Mr Borsak and Mark Banasiak.

Mr Borsak, who is deputy chair of the parliamentary Public Accountability Committee, is also pushing for an urgent meeting of members to consider Mr Perrottet's "fitness" to remain premier.

He is outnumbered on the committee by coalition and Labor MPs whose backing he needs to hold the inquiry. Neither of the major parties are likely to do so.

Committee chair, Greens MP Cate Faehrmann, said it was a "bit rich" of Mr Borsak to push for the hearing.

"His own party hasn't been able to hold him to account for his offensive behaviour in the chamber," she said.

Earlier on Sunday, Mr Perrottet said he was focused on the state, which goes to an election in March.

"I'm focused on taking our state forward ... that's what I've focused on my entire political life," he said in western Sydney.

Mr Perrottet, 40, was also asked if any other future-Liberal politicians were at his 21st party at his parents' home in Sydney's northwest but said he couldn't recall and did not want to "drag" others into it.

"It's not about other people, I made a mistake, it's about what I did," he said.

"The person I am today is not the person I was back then."

Mr Perrottet maintained he has the support of his colleagues, with Roads Minister Natalie Ward adding that the premier had owned his mistake and it was not a reflection of the man she knew.

"What I've seen in Dom Perrottet is a compassionate, kind person who works his guts out every day for the people of NSW," Ms Ward said.

Labor has been contacted for comment.

Asked about the issue on Saturday, Leader Chris Minns said he doubted it would affect the outcome of the state election.

"The people of NSW will make decisions based on many other issues," he said.