The Australian Greens are confident of winning the marginal federal seat of Batman in the upcoming by-election.

Batman’s MP, David Feeny, had to resign from parliament on Thursday after failing to present evidence that he had renounced his British citizenship, making him ineligible to sit in the lower house.

The Green’s candidate Alex Bhathal won the primary vote in the last federal election but Mr. Feeny won after preferences, taking Batman with a margin of one percent.