Strong tensions within the Greens have emerged just months from the federal election, with party leader Christine Milne being accused of running a dysfunctional office and allowing a culture of intimidation.
The accusations follow the resignation of a highly regarded senior employee and come after Senator Milne conceded last month that September's poll would be an uphill battle for the party, which risked losing two Senate spots.
The Greens, who hold the balance of power in the Senate, remain a big force for this year's election and their preferences alone could help decide the fate of candidates in marginal electorates around the nation.
Alexandra Lamb, who was a well-respected media adviser to Senator Milne, quit her job last Sunday after professional clashes with the party's new communications director, Georgie Klug.
Ms Lamb was given half an hour to leave her Parliament House office when a breakdown of relationships led to her resignation.
The incident has highlighted a culture of tension and mistrust inside the party, with insiders saying the Greens' office is fast becoming an unhappy place to work.
Sources say a "bitter, petty and nasty" process was put in train to force Ms Lamb's resignation and was indicative of some measures used against other staff.
"Alex was so dedicated and professional and this shouldn't have happened," one party source said. "But the problem is far deeper than what happened last week. The culture is not good."
Another source said "tensions have skyrocketed" inside the party and "there is an air of chaos and panic as the election gets closer".
Ms Lamb declined to comment, but Fairfax Media has seen a letter she sent to Senator Milne and the office's general manager, Alison Hetherington, last Sunday, offering her immediate resignation and insisting she would not accept a reworked job description handed her two days earlier.
"I received a text message from Georgie demanding that I leave the building within half an hour - which I thought rather emblematic of her management and communication style," the letter said.
Ms Lamb did not supply Fairfax with a copy of the letter or confirm she had even sent it.
Senator Milne would only state that: "Alex made no reports of bullying. She resigned of her own accord."
After further questioning, Senator Milne asked Ms Hetherington to respond in writing, saying: "Senator Milne has never made a practice of commenting on internal staff matters. It is inappropriate to breach the privacy of any individual by commenting further."
The Greens have long been a serious player on the Australian political landscape, but since gaining the balance of power in the Senate following the previous election, their influence has grown stronger than ever.
There have also been recent tensions in the party over policy, with most of the federal party at odds with the Tasmanian branch over the new forests agreement there. All but one of the Tasmanian Greens voted in favour of the agreement, but Senator Milne and former leader Bob Brown, both from Tasmania, are furious that the new act seeks to stamp out dissent.