A Greens volunteer has alleged she was sexually assaulted in the back of a car by another volunteer on federal election night last year.

The allegation is one of three critical incidents discussed but not detailed in an internal report into the campaigns, leaked to Fairfax Media in March.

Zach Ghirardello, a former party member and member of the Greens campaign team, has been advocating on behalf of the 21-year-old woman about the alleged assault since the night, when he was called in to deal with it. But Mr Ghirardello has now gone public, frustrated at his inability to get any action from the Greens hierarchy.

Mr Ghirardello said the ACT Greens had no complaints mechanism and no capacity to deal professionally with the woman's complaint. As a result, she had been fobbed off.

She had wanted an investigation, an apology and new measures to ensure any future incidents would be handled properly. He was also dismayed the alleged perpetrator had remained as a volunteer until about a month after the incident when he had finally been told he made people feel uncomfortable and should no longer volunteer.

He nevertheless remained a party member, leaving the complainant still unable to go to party events without fear of seeing him.

Mr Ghirardello says the nature of the complaint had never even been properly set out to the alleged perpetrator.

And he said the trauma of the event on election night had been compounded severely for the victim by the lack of action since. In February, having come to the end of the road with the Greens hierarchy, the complainant went to police, Mr Ghirardello said.

While ACT Greens convenor Michael Mazengarb told Fairfax the party had since apologised to those affected, Mr Ghirardello said there had been no apology.

The Pru Gell report into the election campaign, completed in February, referred to three critical incidents that remained unresolved and had caused deep rifts within the party.

But emails provided to Fairfax showed former ACT Greens convenor and staffer Sophie Trevitt sent a list of suggested changes on February 13 that would have softened the review.

Ms Trevitt was Greens deputy convenor and election campaigns team convener last year then moved to the staff of Greens politicians Shane Rattenbury and Caroline Le Couteur, where she worked until the end of January.

A reference to volunteers who raised issues during the campaign being called "difficult" by people in leadership positions was "really damning", Ms Trevitt wrote, and a "very serious thing to have in the report".

"I think it would be worth having a conversation with Pru about what this refers to to ensure there is a shared understanding of what was discussed," she wrote.

She suggested taking out sexual assault as an example of a critical incident because of the "reputations of everyone involved - not just the party but also the individuals who are implicated who have no way to respond in this report to assertions".

Another suggestion was to remove reference to the three critical incidents raised within the party through the course of the campaign, because "the advice applies more broadly and it makes sense for that recommendation to apply broadly, and secondly because the party currently has an investigation and resolution processed underway".

Ms Trevitt told Fairfax Media she requested the changes because she was concerned details being published in the review would undermine party investigations and she wanted to be fair to all staff members, party members and volunteers.

None of those changes appear to have been made to the report, and Ms Trevitt was not given the chance to comment on the report before it was finalised, only afterwards.

Ms Trevitt said she raised her suggestions with the party convenor and he decided it was in "the interests of the party" for the report to be provided as it was originally written "so that members could have confidence in the independence of the review".

"I believe that efforts were made at all times to fulfil the wishes of the woman involved in the alleged sexual assault. I am concerned that she does not feel as though this was the case, and I am sorry for any actions that I did not take which could have alleviated the distress she is feeling now," Ms Trevitt said.

Mr Mazengarb also defended the Greens handling of the incidents, saying he believed it had been "appropriate", but said the party was strengthening procedures regardless.

However the victim alleged to the the ABC she had lodged a sexual harassment complaint against the perpetrator previously. Mr Mazengarb said he was not aware of any complaint prior to the assault.

It is understood the party has started an incidents register and last month adopted an updated sexual harassment policy.

The Greens are also reviewing the party's constitution and decision making structures.

It is not the first time this year the Greens have come under fire for their handling of sexual assault claims.

A Sydney woman last month took to Twitter to condemn the party and the NSW justice system for its handling of her sexual assault allegations against a NSW Greens staffer.