Greens candidate Alex Bhathal (right) and Greens Senator Richard Di Natale Credit:AAP The defeat has raised internal rumblings about Senator Di Natale's leadership, but sources have said the only realistic challenger - Adam Bandt - was in lockstep with his leader throughout the campaign and is just as much to blame for the result. Senator Di Natale said the party had made "incredible inroads in Labor’s heartland with a positive campaign on Adani, refugees and inequality". "But it is absolutely clear that we have to get our own house in order if we’re going to win back traditional Greens voters who were turned off by the leaking and sabotage from a few individuals with a destructive agenda," he said. The campaign was rocked in January by the release of a 101-page dossier of complaint against Ms Bhathal, as national infighting between the so called socialist "watermelon" faction and the more centrist politics of its leader moved from the national to the local stage in Batman.

Loading Replay Replay video Play video Play video Before the Batman by-election was announced, Ms Bhathal was pre-selected to contest the next federal election. However that decision seems likely to come under review given Saturday's disappointing result - her sixth loss in the seat. One member of Ms Bhathal's Darebin Greens branch, Sarah Russell, said she resigned her membership on Saturday night because of the "Machiavellian" power play against the candidate and "whatever-it-takes" politics of the party. She said the branchstacking claims were untrue, and the bullying allegations levelled against Ms Bhathal "absurd". Senator Di Natale avoided a traditional election post-mortem press conference on Sunday, opting only to go on ABC TV at 9pm - after the major national TV news bulletins and newspaper print deadlines.

The defeat capped off a horror few months for the party; it lost two senators to the dual citizenship saga, and recently recorded its worst result in Tasmania in three decades. However Greens loyalists point out it also picked up its first Queensland lower house seat in December. Factional leaders have warned the drift of swinging Greens voters "can no longer be ignored" after Labor performed strongly in booths in the south of the electorate that it had long thought were lost to the Greens. In a Facebook post to members, former NSW convenor Hall Greenland said the defeat showed when Labor went left it would attract supporters the Greens thought they had secured. "It happened in Tasmania and of course on an industrial scale in Britain after [Jeremy] Corbyn became leader," Mr Greenland said. "This trend has been staring at us in the face for some time - I wrote about it six months ago - and can no longer be ignored."

Former Greens NSW convenor Hall Greenland. Credit:Janie Barrett Australian Electoral Commission data shows that the swing to Labor in the southern gentrified suburbs of Northcote, Thornbury and Fairfield, - an area the Greens have dominated during the past two elections - was larger than the swing to the Greens in the north, where a higher proportion of Labor leaning working-class voters live. As late as 6pm on Saturday, Labor had all but given up on reclaiming the area south of Bell Street, distributing demographic figures just minutes before the polls closed as a preface to why they might lose the seat. But the final result showed a resounding swing back to Labor, as voters appeared to reward Opposition Leader Bill Shorten's gamble on divided imputation reform and punish the Greens for its flirtation with conservatives after it urged wealthy retirees to vote Green in protest. One local Greens figure said the tactics of running hard on federal issues such as the Adani mine and asylum seekers rather than local concerns like Labor was focused on was a big factor in the loss.