Australia’s independent election overseer has apologised after more than 1800 missing federal ballot papers were discovered at the home of a transport worker.

The discovery comes as the final result in another Sydney seat previously called for the Liberal Party is back in play as further vote counting puts the outcome in doubt.

Bradfield had previously been called for Liberal candidate Gisele Kapterian over independent challenger Nicolette Boele following a closely fought contest.

Absentee and postal vote counting has now narrowed the gap, with Kapterian ahead by just 80 votes as of Wednesday afternoon.

Missing ballots

The 1866 ballots from the Sydney seat of Barton were counted on election night by Australian Electoral Commission workers and their fate does not affect the outcome of the vote in that electorate.

After the votes were first counted, they were supposed to be delivered to the electoral commission’s counting centre for further scrutiny.

The AEC was unable to start with a mandatory second count of the election results because one of the ballot containers hadn’t been returned. All of the others were accounted for.

An authorised transport officer had “inadvertently maintained possession” of the missing container, the commission said.

“It was recovered from the transport officer fully intact, with all uniquely coded security seals unbroken, and without any damage,” a spokeswoman said in a statement.

“All ballot papers were still in the recovered ballot paper transport container and were promptly returned to the counting centre and have undergone fresh scrutiny.

“The fresh scrutiny count matched the initial count and the election in the Division of Barton was unaffected by this incident.”

Labor retained the seat of Barton, with Ash Ambihaipahar replacing the retiring Linda Burney.

While the commission is investigating the incident, it doesn’t believe the transport worker deliberately held on to the ballot container.

“This shouldn’t have occurred, and the AEC is deeply concerned that on this single occasion our process did not prevent the issue on polling night when ballot papers were initially returned,” the spokeswoman said.

“Work is already underway to further investigate this incident to understand what, if any, elements of the return of materials process need to be changed for future elections.”

The electoral commission said security measures and ballot tracking meant the AEC was quickly able to determine that not all ballot papers had been returned.

“The AEC takes ballot paper handling extremely seriously and deeply regrets this incident,” the spokeswoman said.

“The AEC’s manual processes inherently rely on people and occasionally people make mistakes or don’t exercise the best judgement, particularly when under pressure.”

As of Wednesday, the Coalition has just 41 confirmed seats in the 150-seat House of Representatives, while Labor has 93, the Greens have one and other independents and minor parties have 11.

Bradfield knife edge

However, the final result in Bradfield remains on a knife-edge as further vote counting narrows the two leading candidates.

More than 1000 votes are yet to be counted. An automatic recount by the Australian Electoral Commission will be triggered if fewer than 100 votes decide the outcome.

Bradfield is one of four seats – including Flinders and Calwell in Victoria – that remain uncalled.

Vote counting also continues for the Senate, with the final seat in each of the six states still up for grabs.

‘Sexist’ criticism of Ley rejected

 Meanwhile, Liberal women are rallying behind the federal party’s first female leader, branding questions about her ascension as sexist after an official walked back her response to her longevity.

Sussan Ley won the leadership on Tuesday, narrowly beating former shadow treasurer Angus Taylor in a partyroom ballot.

Her Liberal Party deputy is Ted O’Brien, the MP who spearheaded the nuclear energy policy the coalition took to their loss-making May 3 election.

However, Ley was immediately warned she could face a “glass cliff” – a term referring to the appointment of women to top positions during times of crisis, meaning they can be set up to fail.

Charlotte Mortlock, who founded Hilma’s Network, which supports women in the Liberal Party, rejected the claims.

She noted there weren’t similar comparisons made when former opposition leader Peter Dutton became leader after Scott Morrison led the party to its worst defeat in decades at the 2022 federal election.

“We didn’t go pick Sussan Ley off the street to take the fall for the party,” she told AAP.

“She has been the deputy leader, she is second in line, it was a completely logical decision.

“She is an impressive and capable woman and to insinuate she has been given this job for any other reason is incredibly sexist.”

Ley rejected the use of the term at her first press conference as leader on Tuesday.

The promotion of a woman into the top job showed the party was listening to the messages sent by women abandoning the party in droves.

“The number of women supporting us is declining and I want to rule the line under that,” Ley said.

But asked on national television on Wednesday how long Ley would last as leader, Liberal Party’s federal vice president Fiona Scott appeared hesitant.

“I don’t know, I mean a day’s a long time in politics,” she told Nine.

“Well, you know – it could be a day, it won’t be a day. I mean, cheeky, but look you don’t know what the political tides will bring.”

Asked about Scott’s statement, Labor frontbencher Penny Wong said “ouch”.

“That’s not the most ringing endorsement I’ve heard but … I’m going to leave it to the Liberal party to sort this out,” she added.

Later on Sky News, Scott clarified she was joking and that Ley was a fantastic choice.

“I did go on to clarify that I absolutely support Sussan, I think it’s a wonderful step forward,” she said.

Gender equality expert Michelle Ryan said that with more than two decades of parliamentary experience under her belt, Ley was “incredibly qualified” for the job.

“But the timing definitely suggests that it’s somewhat of a glass cliff,” the ANU professor, who coined the term with her research partner Alex Haslan in 2005, said.

“The fact that they’ve come out of an unprecedented loss at an election, and this is the first time a woman is leading – I don’t think those two things are unconnected.

The pool of Liberal leadership candidates was relatively small given the scale of the election defeat, and potential leaders such as Dan Tehan and Andrew Hastie were quick to rule themselves out.

“It’s also interesting that people that might have put themselves forward in a better time are not putting themselves forward now,” Prof Ryan said.

“Whoever was going to take on this leadership position was unlikely to be prime minister.”

Ley’s election was also an effort to show women voters it had changed, Prof Ryan added.

“The glass cliff makes it harder to succeed, but that doesn’t mean success is not possible,” she said.

O’Brien also rejected any suggestion that the leadership duo were some sort of placeholders, saying the Liberal team had united around them and would strengthen over time.

-with Kat Wong and Dominic Giannini, AAP