Ms Cox previously said she chose to quit the minor party to join the Albanese government after some “deep reflection” about her personal values.
In a blistering resignation letter, revealed by the ABC on Wednesday, Ms Cox said the Greens had tolerated racism and failed to protect First Nations women.
“In my experience, the Greens tolerate a culture that permits violence against First Nations women within its structures,” she said in the formal letter.
“In this respect, the party is deeply racist.”
The letter followed Ms Cox’s 2020 claims that she quit the Labor Party to join the Greens because Labor had a “patronising attitude towards women and people of colour”.
Ms Cox’s dramatic defection to the Labor Party last week came after her unsuccessful bid to become the Greens’ deputy leader.
She was the party’s only Indigenous senator at the time of her resignation, after independent senator Lidia Thorpe also quit the Greens in 2023.
Ms Cox’s accusations include claims that the Greens ignored her reports of serious incidents.
This included an altercation at Perth Airport in 2023 involving former ACT Greens candidate and Blak Greens leader Tjanara Goreng Goreng.
Ms Cox also claimed that there were further incidents involving staff who were “isolated by the state and other MP’s offices”.
A Labor MP told Sky News that Ms Cox’s resignation exposed a deeper hypocrisy within the Greens’ approach to Indigenous representation.
The MP said that the Greens “pretended” to represent Indigenous voices but in truth had done nothing to help Aboriginal communities.
They also pointed to the defection of Aboriginal woman Lidia Thorpe from the party, who quit over disagreements surrounding the Voice to Parliament referendum.
Ms Thorpe agreed with Ms Cox that there was racism within the Greens when asked about the resignation letter on Wednesday.
“I think there’s racism everywhere in this country. And there’s a lot of work that the Greens and answer other organisations need to do to stamp that out,” she told the ABC.
Sky News has contacted the Greens for comment.
Greens senator Sarah Hanson-Young blasted her former colleague last Thursday, calling on her to quit the Senate.
“I always think that it’s not fair to the voters and indeed any of the parties involved that if somebody is elected to one party and then jumps ship later on,” she told reporters.
“I do think the honourable thing is to resign from the parliament, but that’s not the rules, and so we’re left where we are.”
The comments follow a spate of criticism surrounding Ms Cox’s abrupt resignation.
Ms Cox only announced she would leave the party after she lost a deputy leadership ballot 9–3 to Senator Mehreen Faruqi.
She then claimed “deep reflection” had led her to realise her values were more closely aligned with Labor’s.
Greens leader Larissa Waters condemned her former colleague’s decision and said she had only been informed of the move an hour before it was announced.
“The Greens are disappointed in Senator Cox’s decision to leave the Greens and join the Labor party as a backbencher,” Ms Waters said at the time.
Ms Cox’s sudden transformation has met skepticism and accusations of political opportunism, particularly given her scathing past criticisms of the Labor Party.
In 2020, Ms Cox said she left Labor because it was “patronising to women and people of colour” and accused the party of caring more about donors than members.
More recently, she accused Labor of having “spectacularly failed” the public through its support for the North West Shelf gas project.
Also resurfacing was her support for the controversial slogan “from the river to the sea” – a phrase Prime Minister Anthony Albanese has publicly condemned.
Adding to the controversy was another leaked 2023 text message in which Ms Cox referred to One Nation leader Pauline Hanson as a “f—ing retard”.
Labor’s apparent willingness to accept Ms Cox, despite these incidents, has drawn comparisons to Mr Albanese’s prior treatment of former Labor Senator Fatima Payman.
Ms Payman was hounded by Mr Albanese after she quit the Labor Party last year to form her own party, Australia’s Voice.
“There is a bit of hypocrisy, of course, about how Labor has responded to this,” Ms Hanson-Young said.
“It wasn’t okay to jump ship for Fatima Payman, but apparently when it’s people coming to them, it’s all okay.”
Ms Payman herself chimed in, saying she was surprised Ms Cox had not suffered the “smear campaign” which she endured after her exit from Labor.
Meanwhile, internal alleged complaints of staff bullying continue to hang over Ms Cox’s legacy in the Greens.
More than 20 staff reportedly quit her office, the SMH revealed, prompting an internal investigation—but the probe was abandoned following her defection.
“There has been a process, and an internal process is hard to run if somebody’s gone to another party,” Ms Hanson-Young said.
Former Labor minister Stephen Conroy added to criticism, calling for Ms Cox to “resign from the Senate” and seek Labor preselection through the proper channels.
“She shouldn’t steal something from the Greens; she should resign and ensure that it’s passed back to the Greens,” Mr Conroy told Sky News.
