Former Greens senator Larissa Waters plans to run again for parliament after being forced to resign her Senate seat because she was a dual-citizen.
Her case, and the case of West Australian colleague Scott Ludlam will be referred to the High Court when parliament resumes on Tuesday.
While Mr Ludlam - who discovered he was still a New Zealand citizen - doesn't wish to return to politics in the foreseeable future, Ms Waters has told party leader Richard Di Natale she has unfinished business.
"After a rollercoaster of a month, I can confirm that I have renounced my Canadian citizenship," the Queenslander said in a statement.
"After a couple of weeks of personal reflection, I have decided that I will put my hand up to recontest the seat, whenever the membership decide that process should commence," she said.
Senator Di Natale wants an audit of every MP's citizenship status, confirming his two senators have been granted a pair while their replacements are decided.
The Greens will support a motion to also refer One Nation senator Malcolm Roberts to the High Court amid questions about his eligibility.