Independent senator Lidia Thorpe has revealed her position on the Voice to Parliament, saying the Blak sovereign movement says "no to the referendum, and no to the Voice".
"Our sovereignty does not coexist with the sovereignty of the Crown," she told reporters on Tuesday.
"We are the original and only sovereign of these lands.
"The Voice is in violation of our ancient protocols. Is not a self-determined body."
On Monday, the Senate within the next two to six months, which, if successful, would see the Voice enshrined in the constitution.
Senator Thorpe, who has consistently pushed for over a Voice, voted against the bill and urged Australians to boycott the referendum.
The Djab Wurrung Gunnai Gunditjmara senator said First Nations people had "never agreed to be governed by the colonial Australian government" and they do not "acquiesce or surrender".
"We do not want to be part of the colonial constitution and the attempt to rule over us and our land," she said.
"We don't accept any colonial mechanism that continues to control us, which is what the Voice ultimately is a part of.
"It has no power, it will be controlled by the parliament."
When , Prime Minister Anthony Albanese confirmed that the Voice representatives would be chosen by the community without government appointments.
The Voice would be allowed to make proactive representations to the government, and the government would seek advice from the body early in the development of policy, he said.
Last month, Senator Thorpe said that she couldn't support the No campaign as it was "looking more like a white-supremacy campaign".
She said she had since changed her position after negotiations with the government over the implementation of the federal recommendations of the Royal Commission into Aboriginal Deaths in Custody and Bringing Them Home report broke down.
"The government have made up all these excuses of why they can't do that, so they didn't come good," she said.
"They could have shown good faith, at least to save people's lives here and now, and they haven't done that."
Senator Thorpe confirmed she would be working on which lays out ,with the other groups that oppose the Voice.
"We're gonna sit in a room with people that we don't normally get along with, so looking forward to that journey," she said.
What is the Blak sovereign movement?
"This country has a strong grassroots Blak sovereign movement, full of staunch and committed warriors, and I want to represent that movement fully in parliament," she said when making the announcement.
"It has become clear to me that I can't do that from within the Greens. Now I will be able to speak freely on all issues from a sovereign perspective without being constrained by portfolios and agreed party positions."
Senator Thorpe said Blak sovereignty was "the ultimate power of the people who come from this land, and that is us, First Nations people across this country".
"We have a right to empower ourselves through our own structures, lands and nations," she said.
"If you want real representation in this country, then only the heads of those clans and nations can give consent."
SBS News has contacted the Minister for Indigenous Australians for comment.