Frontrunner withdraws from Wentworth race

The one-time frontrunner in the Liberal preselection for Wentworth has withdrawn from the race saying he believes the party "should preselect a woman".

Local businessman Andrew Bragg said allegations of bullying by outgoing MP Julia Banks and comments by former foreign affairs minister Julie Bishop about the lack of women within the party were behind his decision.

"I believe these recent events and comments have changed the mood and accordingly I will withdraw my nomination," Mr Bragg said in a Facebook post on Monday.

Woollahra councillor Mary-Lou Jarvis, who's president of the NSW Liberal Women's Council, was previously considered one of the biggest threats to Mr Bragg's preselection chances.

But AAP understands senior Liberals in Canberra now want Sydney East Business Chamber chair Katherine O'Regan to be the party's candidate.

Mr Bragg - who'd received the blessing of former prime minister Malcolm Turnbull to try and take over his seat in Sydney's eastern suburbs - said he was "genuinely shocked" by Ms Banks' allegations.

"Julia Banks' exit from public life is a loss for all of us," he said on Monday.

"Julia is exactly the type of professional woman the Liberal Party must be able to attract and keep in parliament."

There's speculation Mr Bragg stood aside in return for a high-up spot on the party's NSW Senate ticket.

He said in his Facebook post: "I believe in public service and I hope to serve the people of NSW in the future."

Some 210 selectors from Wentworth branches will be involved in the Liberal preselection on Thursday evening.

Any candidate who receives less than five per cent of the vote will be eliminated from any further rounds. The first person to receive more than 50 per cent of the vote is preselected.

Tim Murray is Labor's candidate for the Wentworth by-election. He's being supported by Mr Turnbull's son Alex Turnbull.

City of Sydney councillor Kerryn Phelps is considering whether to stand as an independent with many pundits convinced she'd have the best chance of seizing the seat from the Liberals for the first time since the party's inception in 1944.

Australian Associated Press