Greens senator Lidia Thorpe has welcomed a government assurance that the Indigenous Voice to parliament will not cede First Nations sovereignty on the ABC's Q&A program.
Senator Thorpe has voiced doubts about the proposed Voice, preferring to pursue a Treaty first, and may split from her federal Greens colleagues who have largely backed the Voice.
The senator has voiced skepticism about the Voice proposal and said she needs to be satisfied that it "guarantees First Nations sovereignty is not ceded".
In November Senator Thorpe quizzed the Senate Legal and Constitutional Affairs Legislation Committee on the issue and was told the Voice did not undermine sovereignty.
International law experts including Dr Hannah McGlade have reinforced the view the Voice will not cede sovereignty.
The Greens' First Nations Network has said Truth-telling and Treaty, the other two demands of the Uluru Statement from the Heart, must be pursued as matters of urgency.
Senator Thorpe has also said her support for the Voice could be conditional on the federal government taking action on Indigenous child removals and deaths in custody.
On Monday night she reiterated she wanted to see immediate action.
"If all the states and territories can agree to a voice, then why can't they agree to raise the age of legal responsibility so we can let our children out of these prisons?" she asked.
"I want to see action. Not words. I'm not saying which way I'm going until I see action."
Assistant minister for Indigenous Australians, Malarndirri McCarthy, told the ABC that "sovereignty will not be taken over or lost in this process".
"I'm a Yanyuwa Garrwa woman from the Gulf of Carpentaria. We've never ceded [sovereignty]. Do you think I would stand by and let that happen? So, please, it is a misnomer", she told QandA on Monday night.
Senator Thorpe, a Gunditjmara, Gunnai and Djab Wurrung woman, thanked Senator McCarthy for that assurance but said she would prefer it be written into legislation, if not the constitution.
The co-chair of the Indigenous Voice co-design group, Professor Tom Calma, said state and territory governments were primarily responsible for incarcerations rates, and cited a landmark 2017 report by the Australian Law Reform Commission which called on states to overhaul bail laws.
Senator McCarthy rejected the suggestion the federal government had not sought to reduce Indigenous incarceration rates, citing the work of Senator Pat Dodson.
"I've never worked with anyone who was more passionate of wanting to ensure that the incarceration rates in this country drop," she said.
Greens Senator for South Australia Sarah Hanson-Young has backed the Voice and warned against delay.
"I want to see progress and I don't want this held up just because we can't get to a good place of working together," she told the ABC on Monday in an earlier news broadcast.
"It would be devastating if we didn't get progress on all three (elements of the Uluru Statement of the Heart).
Greens negotiations with the Albanese government on the Voice are ongoing but the minor party's federal leadership is expected to reach a final formal decision next month.
