NSW Premier Dominic Perrottet is in damage control, insisting he has the support of his colleagues after admitting to the “terrible” mistake of wearing a Nazi costume 20 years ago.

Several ministers are standing by Mr Perrottet two months out from the state election.

It comes as the reason behind the premier’s public confession was revealed, with media reporting his hand was forced by his own Transport Minister David Elliott.

Mr Perrottet on Thursday said a colleague had approached him about his 21st birthday fancy dress party, which was why he decided to tell the truth himself.

Multiple media outlets named Mr Elliott as that colleague.

However Mr Perrottet dismissed on Friday suggestions that Mr Elliott was threatening him with the revelation, saying he wouldn’t delve into “private discussions”.

Mr Perrottet also said he was not interested in commentary suggesting the gambling lobby was responsible for pushing Mr Elliott to divulge the secret.

The pair’s relationship has been strained over the NSW government’s plans to introduce a cashless gaming card.

Mr Perrottet said his decision was “not about politics. It’s about doing what’s right”.

“I’ve had a number of colleagues contact me … and I appreciate their support but ultimately it’s not about me. It’s about the hurt and mistake that it caused many people across the state,” he told reporters on Friday, flanked by outgoing ministers Brad Hazzard and Victor Dominello.

Asked if he was confident of leading the Liberals into the elections on March 25, Mr Perrottet answered with a terse “yes” several times.

He referred to the Coalition’s infrastructure track record over the last 12 years as instilling confidence in voters when heading to the polls.

Mr Dominello, who once held the gaming portfolio, said the premier had owned and apologised for his mistake.

“Absolutely I back him in every day of the week,” he said

Other senior coalition figures including Nationals leader Paul Toole and potential leadership rival, moderate Liberal Matt Kean have publicly backed Mr Perrottet.

“He will continue to be the premier and I have no doubts that after March, we will win the election and he will continue in that role,” Mr Toole said.

Shaking, red, and close to tears at points during his press conference on Thursday, the premier said he did not understand the gravity of what the Nazi uniform meant when he naively put it on, aged 21.

Asked where he saw the humour in wearing a Nazi uniform, he suggested all people matured differently based on their experiences.

“I am not the person I was when I was 21,” the 40-year-old said on Thursday.

“At that time, the pages of the history books had not had the impression on me that they should have.”

The incident came a year after Mr Perrottet joined the NSW Liberal Party and two years before he was appointed president of the NSW Young Liberals.

Melbourne University cultural historian Jordana Silverstein said the timing of the premier’s admission was about saving face, rather than genuinely accounting for his actions.

“It’s always been considered offensive, but it’s a matter of whose opinions have been listened to, and respected,” she told AAP.

“(Mr) Perrottet wearing the Nazi costume speaks to the normalisation of anti-Semitism and how acceptable it is amongst a certain segment of Australian society.”

The NSW Jewish Board of Deputies accepted a personal apology from the remorseful premier and said it hoped “this unfortunate incident will serve as a lesson to all”.

– AAP