Aboriginal Tent Embassy representatives say they reject the Uluru Statement from the Heart, and urge Prime Minister Anthony Albanese and incoming Indigenous Affairs Minister Linda Burney to consult with them further.
Speaking days after Mr Albanese promised to commit to the statement, Gomeroi woman and embassy caretaker Gwenda Stanley and Ularoy man Clayton Simpson said the statement threatens First Nations peoples' sovereignty, and lacks a representative body with might.
The statement calls for constitutional and structural change to recognise the sovereignty of First Nations people, including an advisory body to Federal Parliament referred to as a Voice to Parliament, and a commission to oversee a treaty-making process.
In 2017, 250 First Nations representatives attended a convention to discuss the statement, most of whom signed it, but some of whom walked out in protest.
Ms Stanley and Mr Simpson said they both walked out of the convention as a statement against a lack of consultation with delegates.
"A Voice to Parliament is all about respecting parliamentary sovereignty, and we argued that they've had 50 years to make laws for us ... and they haven't done a good job of it," Mr Simpson, who works with the NSW Aboriginal Land Rights Association, said.
"Why don't we start making laws for ourselves through our own Black parliament?"
The embassy supports an independent First Nations parliament over an advisory body, which the representatives say will not have impact.
Embassy representatives also believe a treaty process is a "blank document" which won't bring into effect the embassy's key principles of "reparatory justice and land back and land rights and sovereignty".
"We don't belong in the constitution, full stop," Ms Stanley said. "What we are about is land rights and sovereignty in our country, and having our own Black parliament Voice from a grassroots level."
Ngunnawal elder Serena Williams was also among the delegates who walked out, and said she and her brother William Tompkins were the only Ngunnawal representatives to attend.
"I'm not a citizen, I'm not a part of a constitution, I'm a proud Ngunnawal Wiradjuri woman," Ms Williams said.
"I'm not ceding my rights and my sovereignty to my lands, my waters, my language, my culture, my heritage, all my ancestors - what my ancestors went through," she said, adding that the intergenerational trauma of government policies still lives within her.
She supports an independent representative body for First Nations people, and said her opposition to the statement was not about "causing problems", but standing for what she believes is right, as well as the legacy of her father, who fought for the rights of Aboriginal people.
Ngambri traditional custodian Paul House said the Albanese government would need to carefully consider the statement moving forward and consult inclusively.
"It's been five years since the Uluru Statement was made - unfortunately, many of our people have suffered within that five year period," he said. "So it's a symbolic gesture to announce it, but we need to see some tangible outcomes from what occurred five years ago and how that transpires into today, now, moving forward."
Mr House wants to see the ACT government also recognise the Ngambri people as traditional custodians of the land. He urged the ACT government to establish a Truth and Healing Commission, and establish an eminent panel of First Nations representatives who could consult widely with traditional custodians in the territory.
