It comes as another Green walks away, with former Darebin mayor Kim Le Cerf resigning over the party's handling of bullying allegations raised in the lead up to the Batman byelection.

Her departure marks a dramatic collapse in the branch's fortunes —12 months ago Darebin was the biggest Greens branch in the country, with a Greens local mayor, a Greens state MP in Lidia Thorpe, and hopes for a federal MP in the once-safe Labor seat of Batman (now called Cooper).

Since then, external members have been brought in to help run the Darebin branch, Labor's Kat Theophanous wrested Northcote from Ms Thorpe in the November state election, and the fallout continues from the toxic Batman byelection.

Cr Le Cerf, who will now sit as an independent councillor at Darebin, refused to publicly discuss her resignation from the party.

But party figures have confirmed she is bitterly disappointed in the Greens' leadership’s handling of an internal dispute that undermined candidate Alex Bhathal's campaign in the lead up to the March byelection.

Concerned by the distress the dispute continues to cause, Greens members will now get professional training to deal with disputes.

Party elders admit the Greens have a cultural problem, with internal processes designed to resolve differences "a decade out of date".

Cr Le Cerf and 17 fellow members, including three other Darebin councillors, were behind a 101-page letter sent to the state executive in January calling for Ms Bhathal to be disendorsed. The file was leaked to the media before the March byelection.

The document raised a range of allegations against the six-time candidate, who had reduced Labor's lead in the previously safe seat to just under 1900 votes in 2016.

Some of the allegations appeared minor: Cr Le Cerf said Ms Bhathal had asked her to enter into mediation to resolve their differences, and described herself as feeling "deeply intimidated" over the matter.

Ms Bhathal has strongly denied any wrongdoing.

When the complaint emerged publicly, party leaders were quick to point out an internal investigation established the allegations were unfounded.

But the Greens’ campaign was thrown into disarray, and star Labor candidate Ged Kearney claimed the seat with a 3.35 per cent swing.

In the aftermath, a furious Senator Di Natale said there was no alternative but to find the leakers and throw them out of the Greens.

Despite Senator Di Natale's threats, a review he established recommended no sanctions be imposed against anyone for their role in the campaign.

Through her lawyer, Ms Bhathal declined to comment.

She has previously said that, despite repeated written requests, she had not been given the opportunity to see the allegations against her.

In recent months the Greens have been rocked by a series of allegations of misconduct and poor behaviour among its ranks, including being forced to stand down a candidate for the November state election accused of rape, and accepting the resignation of an upper house candidate, Joanna Nilson, who had posted shoplifting tips on Facebook. The party stood by another candidate, Angus McAlpine, who rapped in 2001 under the moniker "Fatguts" about putting “date rape drugs in her drink” and wanting to hurt his girlfriend after a breakup.

In a statement, Victorian party co-convenors Willisa Hogarth and Colleen Hartland said they were “saddened” to receive Cr Le Cerf’s resignation.

“We wish her luck in her ongoing representation of the people of Darebin, and are committed to improving our processes to resolve the concerns she had expressed,” the pair said.

“We regret the continuing distress being felt by the individuals involved in a dispute in the Darebin branch, and recognise the need for a proper resolution of these matters."

“We know there is more we need to do.”