David Feeney's cavalier approach to politics and process may be about to end his career and Labor's hold on one of its historically safest seats.

Just 18 months after Liberal preferences allowed Feeney to defend his seat of Batman by a whisker from the rampaging Greens, Labor faces the unwelcome possibility of a byelection in a seat he won in July 2016 with just over 51 per cent of the two-party preferred vote.

David Feeney could lose his career. Credit:Chris Hopkins

It would come in the wake of Victorian Labor's thrashing at the hands of the Greens in the Northcote byelection, the state seat that takes in a good part of Feeney's federal electorate.

Pollsters, Labor strategists and journalists were stunned by the 11 per cent swing against Labor, a swing boosted by the Liberals' decision not to run a candidate in the Northcote race.