By Tiffanie Turnbull in Sydney
Prime Minister Anthony Albanese says it would be a "very simple" but "momentous" change. Photo: RNZ / Samuel Rillstone
Australia's leader has unveiled crucial details of a planned referendum which could see it change its constitution for the first time in almost 50 years.
If approved, the vote later this year would establish an Aboriginal and Torres Strait Islander Voice - a formal body for Indigenous people to give advice on laws.
Prime Minister Anthony Albanese argues it would be a "very simple" but "momentous" change.
Constitutional referendums are fairly rare - only eight of 44 have succeeded.
The Voice is being fiercely debated with support and opposition across the political spectrum.
What is the Voice to parliament?
The Voice was recommended by a historic document in 2017 called the Uluru Statement from the Heart.
Drafted by more than 250 Indigenous leaders, the statement is considered the best - though not unanimous - call to action for reforms which affect First Nations Australians.
On Thursday, Albanese announced the proposed wording for a question to be put to Australians in a compulsory vote.
"A proposed law to alter the constitution to recognise the First Peoples of Australia by establishing an Aboriginal and Torres Strait Islander Voice. Do you approve this proposed alteration?"
In an emotional speech, Albanese said the Voice would enshrine "recognition" that Australians "share this great island continent with the world's oldest continuous culture".
"Our nation's birth certificate should recognise this and be proud of it," he added.
Standing alongside, Indigenous Affairs Minister Linda Burney spoke of how she had spent the first 10 years of her life "not being counted".
The proposal, still to be debated in parliament, states the Voice will "make representations" to MPs and policy makers "on matters relating to Aboriginal and Torres Strait Islander peoples".
However, parliament would have the power to decide on the Voice's composition, functions, powers and procedures.
What's the case for it?
Indigenous Australians feel a "powerlessness" when tackling structural problems to improve their lives, the Uluru Statement says.
These problems include having a shorter life expectancy than non-Indigenous Australians, disproportionately poorer health and education outcomes, and higher incarceration rates.
Protesters take part in an "Invasion Day" demonstration on Australia Day in Sydney on January 26, 2022. Photo: Getty Images
Many argue this is often because of a failure to properly consult Indigenous people on solutions.
"Non-Indigenous people [are] making decisions about communities they have never visited and people they do not know," wrote Prof Megan Davis, an Uluru Statement signatory.
What do opponents say?
Some argue Indigenous people are already represented fairly in parliament. It currently has 11 Indigenous lawmakers - representing 4.8 percent of the parliament, a slightly higher percentage than the Indigenous Australian population nationwide.
But Voice supporters counter that MPs represent specific constituencies, not necessarily Indigenous interests.
Other critics say it could act like a third chamber of parliament and potentially veto legislation, but the government has ruled this out.
Support is not universal among Indigenous people, either. Some say a treaty with Indigenous people - a legally binding, negotiated agreement - should be the priority. Australia is one of the only ex-British colonies without one.
Many Indigenous Australians emphasise they never ceded their sovereignty or land. There are fears that being recognised in the constitution could amount to that.
And others argue it's just a symbolic gesture and that money could be better spent on immediate solutions.
What will the Voice look like in practice?
That's not yet certain. If Australia votes yes, legislation designing the Voice will then be developed and debated.
One proposal suggests the advisory body could have 24 members - comprising representatives from each state and territory, the Torres Strait Islands, and remote Aboriginal communities.
Albanese sees the Voice being "an unflinching source of advice and accountability".
Are there global comparisons?
Voice advocates compare it to the First Nations parliaments in Norway, Sweden and Finland for the Sami people.
They're not parliaments in the traditional sense - they are mostly consultative bodies which do not have a formal legislative function.
In Finland, for example, the government negotiates with the Sami Parliament on specific matters like land management and legislative or administrative changes affecting Sami culture.
However, Finnish laws don't prevent government authorities from forging ahead without negotiations.
Why is a referendum needed?
Advocates say the Voice needs to be enshrined in the constitution rather than legislated. Such a change cannot happen without a referendum.
They argue this would give the Voice permanency, insulating it from partisan politics.
For it to succeed, a majority of Australians need to vote yes. There also needs to be majority support in at least four of Australia's six states.
Polling has shown about three-quarters of Australians support a constitutionally enshrined Voice.
The proposal has even won the support of US basketball legend Shaquille O'Neal, who will appear in promotional material.
But the result is far from assured - the last successful referendum was in 1977.
The conservative Liberal Party has previously opposed the Voice, but now says its MPs will vote to decide its position. Its junior coalition partner, the Nationals, oppose the reform.
The Greens party will support the Voice. But its previous Indigenous Affairs spokesperson, Lidia Thorpe, recently left the party over its position - she is advocating for a treaty first.
What next?
Parliament is expected to hold a vote on the proposal in June. If approved, the referendum will happen sometime after September.
If a Voice is established, the Uluru Statement calls for a Makarrata commission - a body to supervise a process of treaty-making and truth-telling about the history of Indigenous Australians.
Implementing a Voice is also seen as likely to create further impetus for an Australian republic. Albanese has already indicated a referendum on the issue is likely if he wins a second term in 2025.
Additional reporting by Tom Housden
-BBC