The former South Sydney rugby league star remained diplomatic over the reasons for his shock resignation during a media conference in Shellharbour, but his manager, BJ Jafari, said he was aware of the racially based comments, but said none of them had been made against him directly.

"I have been told about them and it's a bit disappointing," he said.

Meantime, party sources told the Mercury Mr Boyle had also come in for increasingly vitriolic opposition from angry branch members and at least one MP, after the ALP leadership discarded rank-and-file favourite Neil Reilly and installed the politically inexperienced Mr Boyle.

A well-publicised revolt by rank-and-file members in Gilmore included a public protest outside Parliament House in Sydney.

Party leaders were becoming concerned at Mr Boyle's failure to gain electoral traction after three months on the hustings, and perceived Liberal incumbent Joanna Gash was coasting to victory.

A short and sharp rank-and-file preselection process is now expected and could be finalised within a fortnight.

Mr Reilly now appears the favourite to take on Mrs Gash at the next federal election, and senior party sources believe the advertising executive can put Labor's campaign in Gilmore back on track.

During his media conference yesterday, Mr Boyle looked almost relieved to step away from the often cruel and challenging environment of politics.

He conceded he may not have had enough "political miles" to shrug off the deep divisions within the seat that threatened his electoral chances. Nor was he prepared for the personal attacks on him and his staff.

"It was my decision to step aside for the good of the party," he said.