Wentworth voters will have to wait to find out who's won the Sydney seat with the two front runners agreeing it's too close to call.
The race between independent MP Kerryn Phelps and Liberal candidate Dave Sharma was neck and neck with 50 per cent of the vote counted at 11pm on Saturday night.
Dr Phelps had 51 per cent of the vote on a two-party preferred basis while Mr Sharma had 49 per cent. Both said it was too close to call.
Mr Sharma is confident he can win and return the blue-ribbon seat to the Liberals.
"I'd love to be able to declare the result tonight but I think it's too early to do that," he said at his campaign event at Bellevue Hill.
"I am feeling confident but I want to wait until pre-poll votes."
Mr Sharma, the former ambassador to Israel, believes voter anger has subsided after the "traumatic" dumping of then-prime minister Malcolm Turnbull in August 2018.
He's hoping to reverse the defeat he suffered in October's by-election when Dr Phelps wrestled Wentworth from the Liberals for the first time.
The sitting MP agrees it's still too close to call.
"We have been working against the odds, up against a huge marketing machine, and at this stage we are just slightly ahead," Dr Phelps told AAP.
"We have to wait and see what the postal votes ring in."
The independent MP said her team couldn't have worked harder and they knew it would be close.
"In order to win the by-election I had to achieve a historic swing," she said.
"To hold that would be a massive challenge."