Labor's Mike Kelly has conceded defeat in his New South Wales seat of .

Dr Kelly is trailing Liberal Party candidate Peter Hendy by just over 600 votes.

Dr Kelly has used Twitter to announce he will be conceding this morning, telling his followers "it's over" and thanking them for their support.

A Liberal victory means the seat of Eden-Monaro has retained its tag of a bellwether status.

The seat has gone to the party that has won government since 1972.

The change of government also means Dr Kelly has also lost his role as minister for defence materiel.