Prime Minister Malcolm Turnbull once declared he joined the Liberal party instead of Labor only because his business background would limit his success in the ALP, a former NSW minister claims.
In his political memoir, former state Labor minister Carl Scully also claims Mr Turnbull told him the reason he did not enter state politics was due to his friendship with former premier Bob Carr.
Mr Scully, whose self-published book Setting the Record Straight was launched at NSW Parliament on Friday, recounts a conversation with Mr Turnbull during a "Sydney harbourside function" shortly after he announced he had joined the Liberal party.
Mr Scully says he asked Mr Turnbull: "Malcolm, why on earth did you join the Libs and not the ALP?"
According to Mr Scully, Mr Turnbull's response was: "I could never succeed in the Labor party as it would be unforgiving towards someone who had been a successful businessman".
Mr Scully says he was astonished by the response and asked: "Is that it. That's why you chose to join the Libs?"
"Yes it is," Mr Turnbull reportedly said. "The ALP would just not tolerate someone who had succeeded in business".
Mr Scully says he then asked Mr Turnbull if he would enter NSW state politics with a view to becoming opposition leader and then premier.
But Mr Turnbull reportedly responded: "Bob Carr and I are friends. I couldn't do it to him".
Mr Scully writes the he was "simply astonished that with no stated philosophical commitment to the Liberal Party, he was quite prepared to leave its political opponents in power, rather than take the reins of government away from a personal friend".
Mr Turnbull declined to comment.
Mr Turnbull has previously rejected claims by former Prime Minister Bob Hawke that he had sought to join the Labor party after the defeat of the referendum on an Australian republic.
"I have had many discussions with ALP figures over the years and I've been courted, if you like, and encouraged to join the ALP, which is hardly surprising," he said in 2009.
"I've never been known for being timid and if I'd wanted to be a member of the Australian Labor Party, I would have been one".