O'Farrell could return as leader: expert says

“I do think he can come back from this before the election. It depends on how well his successor does and if there is more to come out from the ICAC,” Dr Chen said.

“But I was very surprised he stood aside.

“I thought this was something was something he could shake off. My reading is he probably forgot about (Mr Girolamo's) gift.”

Dr Chen said while any allegation of impropriety is significant, Mr O’Farrell’s decision should be viewed in a wider context.

“Obviously it is a serious business, but (the wine) was only a minor gift," he said.

“It just reflects the cynical times we live in, in the fact that it is surprising when people resign.

Despite his omission to the inquiry, Mr O’Farrell’s decision to stand aside is a measure of Mr O’Farrell’s integrity, he said.

“It speaks a lot for his character. It is a very pragmatic decision,” Dr Chen said.

“He saw a real risk, in light of the revelations about Arthur Sinodinus, of being tarred with the corruption brush, so he moved to head that off.”

Dr Chen said Mr O’Farrell could return as leader.

“It depends on a number of things, but big the question is what don’t we know? And does Mr O’Farrell know something else that has forced his hand," he said.

Dr Chen said Treasurer Mike Baird was next in line to succeed Mr O’Farell as Premier, but he would be inexperienced in the role, which could increase his reliance on both Coalition partner, the Nationals, and cross-bench members in the Shooters and Fishers Party, who hold the balance of power in the Upper House.

“Under ideal circumstances, Baird would have had more time to be groomed for the role," Dr Chen said.

“So his elevation might change the government’s relationship with the Shooters, who are upset over the winding up of the Game Council, which was previously responsible for regulating firearms in NSW.

“They blamed O’Farrell, but a new Premier could gain a lot more support from the Shooters if they play their cards right, but the new premier will have to give some concessions – such as reinstating the Game Council.

“If Baird is Premier, he will have to lean on (the Nationals) more because he has the training wheels on – so the Nats could have more authority in the next premiership.”