Liberal candidate Fiona Kotvojs says she will not concede defeat in the Bega by-election despite a double-digit swing against her and Premier Dominic Perrottet congratulating her Labor opponent.
Dr Michael Holland is set to claim a historic victory for the Opposition: with 25 per cent of the vote counted, the swing to the ALP was more than 13 per cent.
It had been held on a 6.9 per cent margin by outgoing MP Andrew Constance for 17 years and had never been won by Labor.
Ms Kotvojs last night declined to concede.
"As we move forward and as counting continues tomorrow, and the next day and the day after because ... none of the postals have been counted and only a few of the pre-polls," she told media in Batemans Bay.
"As the counting continues, tomorrow I'm going to be at Cobargo show."
More than 50 per cent of people in the electorate cast their vote early at pre-poll centres or by using postal ballots — the Electoral Commission will not start to count the latter until next Saturday.
ABC chief elections analyst Antony Green said Labor would win Bega, "assuming that the postals and pre-polls aren't totally different than every other previous election".
Bega was one of four seats up for grabs in Saturday's NSW by-elections.
Liberal candidate Tim James claimed victory in Willoughby while the Nationals won Monaro, although there were swings against the government in both.
Labor retained Strathfield in a tighter race.
Ms Kotvojs, who has been an unsuccessful Liberal candidate twice before, delayed conceding the 2020 Eden-Monaro by-election.
Speaking at a function in Sydney last night, Mr Perrottet was less optimistic about the result.
"It doesn't look tonight that Fiona will win that seat," he said.
"I want to congratulate … Dr Michael Holland, he has big shoes to fill and I'm sure he'll do a great job representing Bega."
Dr Holland had earlier claimed victory, telling the ABC the by-election had been a "plebiscite".
"It's been a reflection of the community's response to the current government and our need to be heard with our concerns," he said.
"I think it's time to celebrate a bit of history."
Labor winning Bega means NSW's Coalition government has been plunged further into minority.
Mr Perrottet could need to make deals with independents and minor parties to pass legislation.
Health a big issue in Bega
Health was seen as a major issue in the South Coast electorate.
Dr Holland, a former long-time obstetrician and gynecologist, in November resigned from the Southern NSW Local Health District, arguing a review into maternity services at Moruya Hospital had not addressed alleged "unsafe" practices.
When the by-elections were called, Labor's Shadow Health Minister Ryan Park encouraged him to run.
"No doubt it's a very big swing," Mr Constance told the ABC last night.
"The voters in the electorate have voted on health, that's clear this evening."
At his official function last night, Dr Holland said he was looking forward to representing the area.
"The community is angry, disappointed and in many ways, they feel powerless to do anything," he said.
He ran a campaign focused on problems with the local health service.
"So having someone with medical knowledge … is a way to navigate the way to improve the services," he said.
