Labor's Libby Coker has vowed to ensure the Coalition Government delivers on a swag of expensive election commitments, after the Liberal Party's Sarah Henderson conceded defeat in the marginal Victorian seat of Corangamite.

Key points: Ms Henderson has held Corangamite since 2013

Ms Henderson has held Corangamite since 2013 The seat was notionally Labor after a redistribution

The seat was notionally Labor after a redistribution Visit the ABC's live results page

With 81 per cent of the vote counted, Ms Henderson trails her Labor opponent, Libby Coker, by more than 2,200 votes.

In a statement posted to Facebook on Wednesday night, Ms Henderson said it had become clear she would not be able to catch up to Ms Coker.

"This was a tough campaign and whilst I am obviously disappointed, I know that the people of Corangamite will benefit for years to come from the commitments I secured which will be delivered by a re-elected Morrison Liberal Government," she said.

Sarah Henderson recorded swings to her in some polling places. ( ABC News )

Ms Henderson, a former ABC television journalist, faced an uphill battle to retain the seat after a redrawing of the electorate's boundaries made it notionally Labor, but achieved swings to her in a number of polling places.

She polled ahead of Ms Coker at several polling places west of Geelong, including Birregurra, Ceres, Freshwater Creek and Moriac.

Ms Coker found greatest support in her coastal home town of Aireys Inlet, where she received 72 per cent of the two-candidate preferred vote.

Ms Henderson said she was proud of her team's strong campaign.

"This was a seat that many people had written off just a few months ago and yet we have come so close," Ms Henderson said.

"We didn't play dirty, we focused on policy not personality and we never forgot that every community matters."

Seat attracted $2b in Coalition commitments

Ms Coker, a former teacher, first ran for the seat in 2016.

Interviewed on ABC Radio Melbourne this morning, she nominated climate change, wages and funding for health and education as issues that had contributed to her victory.

She said she would fight to ensure the incoming Morrison Government delivered more than $2 billion in promises it made — including for fast rail to Geelong — in its efforts to retain the seat.

"I will be keeping this government to account on every one of those commitments," she said.

"That will be my first job when I enter Parliament."

Labor supporter Nick Harding said environmental issues and Ms Coker's personal recognition helped Labor achieve a swing in Corangamite, despite the party failing to secure a swing nationwide.

"She's been a feature down here for a long time," he said.

"I noticed from the counts at the Aireys Inlet booths there was a significant swing and I suspect that was down to a personal factor."

Local resident Diana Trewenack said she was looking forward to a change.

"I can't complain about Sarah [Henderson], she did a wonderful job. But it is nice to have Libby in. She is a real local here."

Sarah Henderson (left) has conceded Corangamite to Labor's Libby Coker (right). ( ABC News: Luke Stephenson, Cameron Best )

Ms Henderson, who lives on the eastern side of the electorate, nominated the duplication of the Princes Highway between Winchelsea and Colac, a new international terminal for Avalon Airport and a safety upgrade to the Great Ocean Road among her achievements.

Ms Henderson supported Malcolm Turnbull in last year's Liberal leadership contest, telling ABC Radio Melbourne at the time that she had been offered a ministry to defect to the Dutton camp, an offer she rejected because "to be rewarded for an act of treachery would be a terrible thing".

Mr Morrison promoted her to the outer ministry after he became Prime Minister last year, making her Assistant Minister for Social Services, Housing and Disability Services.

Her defeat reduces the number of senior female Liberal MPs available for selection for Mr Morrison's frontbench.

While Labor had hoped to win a number of seats from the Liberal Party in Victoria, it appears likely to only gain Corangamite and the Frankston-based seat of Dunkley, which was also notionally Labor following last year's redistribution.

Labor went close to snatching Chisholm, the seat in Melbourne's eastern suburbs vacated by Liberal defector Julia Banks, but Labor's Jennifer Yang appears certain to fall short of Liberal candidate Gladys Liu, who would become the first Chinese-Australian woman to sit in Federal Parliament's Lower House.

With almost 83 per cent of votes counted, Ms Liu leads Ms Yang by almost 1,400 votes.