A leading Indigenous campaigner for a voice to parliament fears failure would forever impact opportunities for reconciliation between Indigenous and non-Indigenous Australians.
Founder of the Cape York Institute and From the Heart Advisory Group member Noel Pearson said Australians needed to understand what was truly at stake.
"The question that will be put is do we recognise Indigenous people in the constitution, and if we say no to that then I can't see how the future will be anything other than protest," he said.
"The Indigenous presence in this country will forever be associated with protest rather than a proper response by the Australian people to this call for recognition and the achievement of reconciliation."
The federal opposition has called for more detail on the proposed body, which would be established after a successful referendum, but Mr Pearson said such demands were a diversion.
"What is at stake is the chance for reconciliation," he said.
"If this referendum is kiboshed through game play and a spoiling game by the opposition we will lose the opportunity, I think, forever."
Mr Pearson said details of the body would be in legislation made by the parliament but the referendum itself was about the constitution.
"The Australian people are being asked to vote on a constitutional amendment," he said.
"All of the power lies with the parliament and it's a complete diversion to demand these details."
Shadow attorney-general Julian Leeser, who has previously advocated for a voice to parliament, threatened to withdraw his support unless the government provided further details.
"People want to know what the body is going to do, who is going to be on it, how will they be selected, what will its powers and functions be. The government doesn't seem to want to explain that," he said.
"There are real dangers ahead if (the government) don't provide the answers to the reasonable questions that Australians have."
Prime Minister Anthony Albanese said details on the question were released last July and he had personally met with Opposition Leader Peter Dutton on the matter more than five times.
"I released what Australians will potentially be voting for, a draft question and draft constitutional change," he said.
"There hasn't been any suggested changes to that draft from the coalition and they have had more than six months."
The prime minister said following a successful referendum to establish a voice, parliament would decide how the advisory group would operate.
"The voice won't be a funding body, it won't be an administrative body ... it will simply be an advisory group," he said.
"Its advice doesn't have to be taken but it does have to be heard."
The National Party confirmed last year it would not support the referendum, triggering the defection of lower house MP Andrew Gee.
Nationals Leader David Littleproud said his party did not have malicious intent by not supporting the voice.
"We have members of parliament that actually have lived experience on these communities ... the biggest disadvantage is in rural and remote areas," he said.
"What we're saying is another layer of bureaucracy will not change this."
While a date for the referendum has not been set, it will take place before the end of the year.