The fight to win Malcolm Turnbull's safe Sydney seat is heating up, in no small part because the ousted Liberal prime minister's son has called on political donors to side with Labor.
ALP candidate Tim Murray says his friend Alex Turnbull spoke with him shortly after Malcolm Turnbull lost the Liberal leadership and asked what he could do.
Mr Turnbull's son has taken to Twitter to encourage people to donate to Labor ahead of the Wentworth by-election and shared campaign material.
Mr Turnbull told reporters from New York his son was able to express himself now that he was out of office.
The Liberal Party preselection is down to three names including Peter King, who lost the seat to Mr Turnbull in 2004.
Tony Abbott's sister Christine Forster has declined to run for Liberal preselection but City of Sydney councillor Kerryn Phelps is considering running as an independent.
A by-election date is yet to be set but will likely be in mid-October.
