Labor candidate and former mayor Kristy McBain has claimed victory, as vote counting continues in the Eden-Monaro by-election.
On Monday morning Liberal candidate Fiona Kotvojs sat 1303 votes ahead of Ms McBain, who claimed victory on Sunday, on first preference counts, but just over 700 behind on the two-party-preferred vote, with a slender swing of 0.44 per cent.
Dr Kotvojs is yet to concede defeat, with the Liberal Party saying on Monday "vote counting continues, and more votes are coming in".
Postal votes were still being counted, with 16,840 issued and 10,995 received, and voter turn-out was almost eight per cent down on last year.
Ms McBain, who was almost brought to tears as she spoke on Sunday, said she plans to work with all levels of government.
"I'm really looking forward to getting to work - fighting for more funding for our bushfire-affected communities during the recovery," she told ACM on Monday.
"A key priority will be fighting for better roads and transport links for our regions."
The 37-year-old is now set to become the electorate's first female representative in Canberra when she is sworn in in August.
Despite an overall swing of 3.2 per cent to the Liberal Party, Ms McBain saw swings in her favour at many Bega Valley booths.
The by-election was triggered by the early retirement of Labor's Mike Kelly, who is now working for US big data company Palantir Technologies, due to ongoing health issues.
"Delighted at the attention we drew to our issues. As painful as leaving has been this has made it all a little bit easier," he said on Twitter after the by-election.
Prime Minister Scott Morrison described both as "very fine candidates", and commended Ms McBain on her campaign.
"With history against us, the strong performance of the Liberal primary vote in an expanded field in a by-election held by the Opposition is welcome," he said on Twitter.
"Regardless of the result there is still much to do right across Eden-Monaro, and as a government we remain committed to that task."
Labor leader Anthony Albanese said on Monday he "can't wait to welcome" Ms McBain to Canberra.