Dr Hendy congratulated Dr Mike Kelly, saying he hoped he could provide the representation in Parliament that Eden-Monaro deserved.

"It would appear that we have fallen short of the votes required to retain Eden-Monaro," Dr Hendy said in a statement.

"I'm very proud to have delivered better infrastructure and services across the electorate, including improved mobile phone coverage, record spending on local roads and rolling out the National Broadband Network.

"I am very proud of the campaign my team and I waged: we focussed on policy and presented a positive plan, but above all, we retained our honesty and integrity."

Eden-Monaro looks set to produce a historic result in the 2016 federal election as the positive swing to Labor could spell the end to the seat's bellweather status.

Ex-army lawyer Dr Kelly, who held the seat from 2007-13, had a swing towards him of 6.5 per cent and had 53.6 per cent of the two party-vote as of Saturday night when 83 per cent of votes in the electorate had been counted.

On the ABC on Saturday night, Dr Kelly dubbed Dr Hendy a "unicorn", saying voters had heard of him, but never seen him.

The seat of Eden-Monaro is well known for having been won by the party that formed government in every election since 1972.

The diverse electorate includes Queanbeyan, Yass, the snowfields gateway towns of Jindabyne and Cooma and seaside villages such as Narooma and Eden. However, there was a major redistribution before this election, although it was meant to have made the seat safer for the Liberals.

Dr Hendy and Dr Kelly have been contacted for comment.

The morning after election day, there remained significant uncertainty about the final results.

Despite a disappointing performance, Prime Minister Malcolm Turnbull said he was confident the Coalition could form a majority government but was unable to claim victory based on the very tight results.