Tony Abbott's sister, Christine Forster, and NSW independent Alex Greenwich could contest the seat of Wentworth if it is vacated by Malcolm Turnbull.

Voters in the blue-ribbon electorate, held by Mr Turnbull for 14 years, could soon be headed to the polls for a by-election after he declared would leave the Parliament "not before too long".

Scott Morrison emerged victorious as the country's next leader after a leadership spill that has exposed tensions and changing allegiances within the Liberal Party.

A spokesman for Ms Forster, currently a Liberal councillor in the City of Sydney, told the ABC she was considering a tilt at Wentworth.

"She's had a few people approach her to run for it," he said.

"She's going to consider it if and when the seat becomes vacant."

Independent Sydney MP Alex Greenwich, who played a pivotal role in last year's campaign for same-sex marriage, has also been approached.

"Many people are urging me to consider running and generously offering their support," he said.

Mr Greenwich believes a community-based independent could win the seat.

"History shows we do well at state and local elections."

"[The] focus for me at the moment is the job I love as the member for Sydney in the NSW Parliament."

Independent Member for Sydney Alex Greenwich has been approached. ( ABC News: Marco Catalano )

Another potential contender is James Brown, the husband of Mr Turnbull's daughter and current President of RSL NSW, however he addressed speculation in a newsletter on Thursday.

"Let me be clear: I am fully engaged in the task of returning this league to be the pre-eminent organisation caring for veterans and their families," Mr Brown wrote.

Party elder weighs in

The choice of who to run as a candidate will be critical for the Liberal Party, admits former leader John Hewson.

While Mr Turnbull enjoys a margin of 17 per cent, Mr Hewson — who held the seat from 1987 to 1995 — warns nothing can be taken for granted.

The electorate includes some of Australia's most expensive properties in affluent suburbs including Vaucluse, Bondi and Bronte.

John Hewson, the former Liberal Party leader, says the decision of who to run in a Wentworth by-election will be critical. ( ABC News )

However Mr Hewson said it is also diverse.

"People focus on the wealthy end of the seat," he said.

"But in my day I used to be proud of the fact that I think I had the wealthiest and the poorest people in the country in the one seat."

The Liberals will also be wary of sentiment from voters who have been put off by the messy leadership debacle.



"If the electorate wants to register a protest vote against the sort of disloyalty they've seen, there's a mechanism by which they can do it," Mr Hewson said.

"You'd have to guard against that."

Locals divided

On the streets of Wentworth, opinion is mixed.

While some locals said they were "devastated" by Mr Turnbull's ousting, others believed he'd "had his opportunity" and had "fluffed the energy policy".

The Greens will run Waverley's deputy mayor, Dominic Wy Kanak, while Labor has chosen businessman Tim Murray.

Mr Hewson said Wentworth included many traditional Liberal voters, but also a big Green element.

"A strong Independent, a strong Green [or] a strong Labor candidate could pull quite a few votes off a sitting or a new Liberal candidate," he said.

Mr Wy Kanak, who has served as deputy mayor since last year but been in local government for nearly two decades, said there is already a strong show of support for his party in the area at council level.

Boats docked at Vaucluse, one of the affluent suburbs taken in by the seat of Wentworth. ( Reuters: Daniel Munoz )

"We can convert that into a strong result in the federal election," he said.

"I've been to actions here where there's obviously a feeling of social justice amongst the Wentworth community."

ABC elections analyst Antony Green said the timing of when Mr Turnbull leaves is also key.

"If he leaves it several weeks, it will be too late in the cycle to have a by-election, especially when we remember that voters in Wentworth already have to vote twice in the first six months of next year," he said.