Former Green MP Darleen Tana has launched legal action to try prevent their former party from ousting them from Parliament.
Green delegates are due to meet on Sunday to decide whether to invoke the waka-jumping legislation, with the caucus calling Tana unfit to be an MP.
Green co-leader Chlöe Swarbrick fronted a hastily-called media conference at Parliament on Wednesday afternoon, revealing that Tana had filed legal proceedings.
Tana had applied for an interim injunction seeking to block the Greens' meeting from taking place, Swarbrick said, as well as a judicial review of herself, co-leader Marama Davidson, and the party.
"It is what it is," Swarbrick said.
A hearing is set for 10am tomorrow at the High Court in Auckland.
Tana, who uses they/them pronouns, has been contacted for comment.
Tana quit the Greens in March this year after an inquiry into migrant exploitation, but they want to remain in Parliament as an independent.
The party has the power to boot Tana out of Parliament using the waka-jumping law, but the Greens have a long history of opposing the use of such rules.
With that in mind, the party has put the question back to the membership with a meeting of 200 delegates planned for Sunday morning. As of this afternoon, that meeting remains in train.
Speaking to reporters at Parliament, Swarbrick said the Greens were now working through their legal options, putting "one foot in front of the other".
"We're dealing with what we've got now right in front of us. Our actions will continue to be led and centred around Green Party values."
Swarbrick said she was limited in what she could discuss due to "confidentiality and legal advice" but gave an assurance would update members and the public following tomorrow's court hearing.
"We have done absolutely everything we can here to ensure that we can be fully transparent and will share all of the information in due course."
Asked what she thought members would make of the latest development, Swarbrick gave the strongest indication yet that the membership was gearing up to use the waka-jumping legislation.
"Let's not put the cart before the horse, but I've been pretty straight up about the fact that our membership has been incredibly frustrated by how things have played out here," Swarbrick said.
"There is a very strong sense that people would like some accountability and responsibility taken."
Swarbrick would not be attending the hearing herself. She said the Greens' lawyer was operating on a pro bono basis: "I'm assuming that this is a pretty interesting case".
Tana last week wrote a letter to the Green co-leaders, arguing that the party had no grounds to invoke the waka-jumping law against them.
In response, Otago University law professor Andrew Geddis told RNZ he believed Tana was "grasping at straws".