In a trend that threw the outcome into doubt early on Sunday, Mr Sharma secured about 64 per cent of the postal votes being counted and appeared on track to close the gap and possibly win the byelection. This trend was suddenly reversed when the AEC checked the count at polling booths in suburbs including Bellevue Hill, Bondi and Bronte, adding more than 700 votes to the Phelps camp and giving her a significant lead. Fairfax Media was told the Liberals believe there is only a "very, very slim chance" the postal votes yet to arrive will change the outcome. “I’m a pretty fatalistic sort of person. This is something I can’t control, it’s in the hands of the voters, still,” Mr Sharma told Sky News on Sunday night. “I’m behind Kerryn and it will be hard to make that up.”

The AEC issued 12,788 postal vote envelopes and has only received about 80 per cent of them in recent byelections. It has already received 6890, leading to estimates there are another 3300 yet to come. If Mr Sharma gained 64 per cent of another 3300 postal votes he would still fall about 700 votes short of Dr Phelps. Loading He would also fall short if he gained 64 per cent of all the 5602 postal votes that were issued but not yet received back by the AEC. In this scenario, he would gain 3585 votes while Dr Phelps would gain 2017 votes. This represents a generous forecast of the outcome for Mr Sharma but it would leave him with 39,678 votes, behind Dr Phelps with 39,736 votes. He would lose by 58 votes.

Other uncertainties hang over the count, however, given the scope for changes to the tally from further checks on the results at various polling booths beyond those checked on Sunday. A recount will be triggered if the outcome is decided by fewer than 100 votes or if the result is challenged. The result has provoked Liberal anger at former prime minister Malcolm Turnbull for not doing more to convince voters to back Mr Sharma and instead remaining silent as polling day neared. Loading Prime Minister Scott Morrison acknowledged the anger from voters over the removal of Mr Turnbull on August 24 while others said the debate over the leadership spill meant the Liberal Party should apply new rules to prevent it being repeated. Liberal MP Trent Zimmerman, who supported Mr Turnbull during the spill, is calling for new party rules to make sure there is a “cooling off period” between a spill motion and the ballot on the leadership.

Writing in Fairfax Media on Monday, Mr Zimmerman also calls for the adoption of UK Conservative Party rules that prevent a new challenge within a certain period, such as 12 months, as well as a shift to four-year terms for Parliament. “If the Liberal Party is to restore faith in its ability to provide the stability that, for most of our history, has been our strength, then change must happen,” he writes. Mr Morrison acknowledged the damage to the Liberal campaign from the lingering anger over the toppling of Mr Turnbull. “The events of two months ago angered and outraged many Liberals, and particularly those in the seat of Wentworth,” Mr Morrison said. “That’s on us, the parliamentary Liberal Party, those who serve in the parliamentary ranks.

Kerryn Phelps and Dave Sharma are battling it out to win Wentworth. Credit: Mr Turnbull held the seat with 67.75 per cent of the vote in two-party terms but the latest count showed the Liberal Party getting only 48.72 per cent in the byelection, a setback of 19 per cent and one of the biggest swings on record. The Keating government suffered a swing of 23.6 per cent in the Wills byelection in 1992 but the result was invalidated on constitutional grounds. Setting this aside, the biggest swing against a Labor government was 16.1 per cent in the Canberra byelection in 1995 and the biggest swing against a Coalition government was 12.4 per cent in Werriwa in 1952. Loading Several Liberals who campaigned in the byelection told Fairfax Media they could have won with stronger support from Mr Turnbull, although federal Liberal president Nick Greiner said he doubted this would have saved the seat.