The independent member for Wentworth, Kerryn Phelps, has conceded defeat to Liberal candidate Dave Sharma, saying she was proud of what she achieved in just seven months.

Key points: Liberal candidate Dave Sharma is leading the count in Wentworth by more than 2,500 votes

Liberal candidate Dave Sharma is leading the count in Wentworth by more than 2,500 votes Independent Kerryn Phelps was elected in a by-election last year

Independent Kerryn Phelps was elected in a by-election last year Dr Phelps said she was most proud of fighting to remove children from Nauru and the passing of the 'Medevac bill'

Dr Phelps defeated Mr Sharma in a historic by-election last year but in Saturday's federal election Mr Sharma finished on top.

Nearly 77 per cent of the ballots have been counted and Mr Sharma leads by more than 2,500 votes.

Mr Sharma said Dr Phelps ran a "tough and competitive campaign" but said he pulled ahead in the tight race because their constituents were voting on national issues.

"I was helped by the tailwind of a strong national campaign," he said.

"The minds of voters were focused on the national choice they were making this time around."

The new Wentworth member also thanked former prime minister Malcolm Turnbull — who vacated the seat after he was ousted from the nation's top job last year — for his support.

Dr Phelps said she and her team could not have worked any harder.

She also acknowledged her supporters who believed in doing politics "differently".

"They believe that there was a sensible centre in Australian politics," she said.

"That it wasn't always about right and left, that it was about right and wrong."

Dr Phelps successfully fought to remove children from Nauru as well as pass the "Medevac bill" which allowed for the transport of sick refugees to Australia for medical care.

She said she hopes Prime Minister Scott Morrison will continue to ensure remaining refugees on Manus and Nauru receive the attention they need without delay.

Dr Phelps won booths around Bondi Beach and Darlinghurst, but Mr Sharma outpolled her in the electorate's most affluent suburbs like Double Bay and Vaucluse.

Dr Phelps's by-election win last year was the first time the seat in Sydney's affluent eastern suburbs had not been won by the Liberals, or its predecessors, since federation.

At the by-election, which was sparked when Mr Turnbull was ousted as prime minister, voters punished the Liberal Party and Mr Sharma suffered a swing of almost 20 per cent against him.

Both he and Dr Phelps increased their primary vote this time around.

Mr Sharma, a former ambassador to Israel, said during the campaign that anger over Mr Turnbull's knifing had subsided and people in Wentworth were focused on choosing the government.

The vote was expected to be tight, however Liberal Party insiders were confident the mood had shifted in the blue-ribbon seat.

Campaigning ahead of the federal election was particularly dirty, however.

Dr Phelps was targeted with several abusive emails — some included anti-Semitic remarks and claimed she was ineligible to stand, while others were homophobic and named her children.

Dr Phelps — a former head of the Australian Medical Association — campaigned on climate change and vowed to stop the Adani coal mine as well as other new coal projects.

The new independent member for Warringah, Zali Steggall, said she was sad and "disappointed" about the result in Wentworth.

"She's been a great Member for Wentworth," Ms Steggall said.

"She's made a phenomenal contribution to Australia at large and I think she is very hard working and very good."

Dave Sharma lost the Wentworth by-election last year by 1,850 votes. ( ABC Radio Sydney: Dayvis Heyne )

But Ms Steggall said she had met Mr Sharma as well and described him as "moderate" and "reasonable".

"I am sure that our views probably align even on a number of issues," she said.

Wentworth was one of the two seats in NSW considered too close to call following Saturday's federal poll.

The seat of Macquarie, in NSW's Blue Mountains, is still considered "in doubt".

With 84 per cent of the vote counted, Labor's Susan Templeman — the incumbent member — is ahead with 50.2 per cent of the two-party preferred vote with the Liberal Party's Sarah Richards on 49.8 per cent.