Independent senator Lidia Thorpe is considering abstaining from voting on legislation to enable the Voice referendum in the Senate but has ruled out supporting the No campaign.
The senator told ABC's Insiders program she is neither in the Yes or No camp for the Indigenous Voice to Parliament.
"The Yes vote is to allow for a powerless voice to go into the Constitution," she said.
"Yes, we don't know what this looks like, it could be one person, it's up to the parliament to decide what the voice looks like.
"So I can't support something that gives us no power, and I certainly cannot support a No campaign that is looking more like a white-supremacy campaign that is causing a lot of harm.
"So I'm considering to abstain from the up-and-coming vote."
The Senate will vote next month on legislation that will pave the way for Australians to vote later this year on whether a Voice to Parliament — which would act as an independent advisory body for First Nations people — should be enshrined in the constitution.
Senator Thorpe, who has consistently pushed for a treaty with First Nations people instead of a Voice to Parliament, said she would look to amend the bill to acknowledge the "sovereign status of First Nations peoples in this country".
"The Voice is going to be decided by parliamentarians on who it is, what it is, what it looks like, what it does — that is no power to the people," she said.
"We need to start discussing sovereignty in this country that will ultimately bring power to First Nations people, which is what my amendment talks about."
Referendum bill debated in parliament
Politicians in the lower house spent last week debating the referendum bill, delivering impassioned speeches for and against a Voice to Parliament.
Opposition leader Peter Dutton hardened his stance against the proposal arguing it would "re-racialise our nation".
"Changing our Constitution to enshrine a Voice will take our country backwards, not forwards.
"It will have an Orwellian effect where all Australians are equal, but some Australians are more equal than others."
Prime Minister Anthony Albanese used his speech to accuse the Liberal leader of amplifying misinformation, and urged all Australians to be on the "right side of history".
"It is disappointing but not surprising that the loudest campaigners for No vote, have already been reduced to relying upon things that are plainly untrue," he said.
Mr Albanese said a Yes vote is the next step in reconciliation.
"The choice we have now — as politicians and as citizens — is are we going to repeat those same mistakes? Should we just keep doing what we have been doing for such a long period of time and expect a different outcome?" he asked.
"Imagine that after generations of being sidelined and ignored, you are finally given an opportunity to change it. To be heard."
More than 90 MPs delivered speeches last week on the referendum including former prime minister Scott Morrison, who is opposed to the constitutional change, and Liberal backbenchers Julian Lesser and Bridget Archer who spoke out in favour of the Voice.
The lower house will continue debating the bill this week before it proceeds to the Senate.
Thorpe to lodge human rights complaint against Greens
During the same interview on Insiders Lidia Thorpe flagged she was lodging a complaint with the Australian Human Rights Commission over alleged racist treatment from the Greens party while she was a member.
The Independent senator refused to give more details as she awaited further advice from her lawyers.
"That's a conversation I need to have with them. I don't want to say any further. But, yes, I've experienced racism all my life in every workplace, and the Greens were no different," she said.
"It's the foundation of these institutions that are racist, that allow racism to occur. I think we all need to look at ourselves within and eradicate that and make our workplaces safer."
In Senate estimates earlier this week, she accused her former colleague Sarah Hanson-Young of failing to act on racism within the party, which the Greens senator rejects.
"The Greens are not aware of any proceedings against any of its MPs or the party. The Greens are committed to stamping out racism wherever it occurs, in workplaces everywhere and in institutions like Parliament," a party spokesperson said.
Ms Thorpe quit the Greens Party in February.
