NSW Premier Mike Baird must explain why he appointed Liberal fundraiser Nick Di Girolamo to a state board despite receiving advice to the contrary, Opposition Leader John Robertson says.

The Labor leader said that Mr Baird, on his first full day as premier on Friday, "must detail how he is going to deal with the toxic culture within the Liberal Party of lobbyists and donors".

Mr Baird on Thursday took over as premier following the resignation of Barry O'Farrell who had given misleading evidence to NSW's corruption watchdog about the gift of an expensive bottle of wine from Mr Di Girolamo.

It's been revealed that Mr Di Girolamo was rejected for a position on one state board when advice was given that he lacked appropriate experience, but he was later appointed to another board with Mr Baird's backing.

Mr Robertson told reporters on Friday that Mr Baird must explain to the people of NSW "why he appointed Nick de Girolamo to a lucrative state board despite receiving advice to the contrary".

He said if Mr Baird did not provide such an explanation "the public will rightly think he's got something to hide".

"Mike Baird needs to explain to people how it is he's going to clean up politics because at the moment the lobbyists and the donors are running the Liberal Party."

Mr Robertson challenged Mr Baird to work with him to implement Labor's new standards for political behaviour of greater transparency and accountability.