Mr Wyatt urged a cautious approach to constitutional recognition of Aboriginal and Torres Strait Islander people out of concern at the risk of a devastating defeat that would set the cause back a generation.

Indigenous leader Noel Pearson also changed tack on his referendum push on Wednesday, conceding the model should be fleshed out before being put to the Australian people, a shift from previous arguments the vote could take place first.

After being sworn in on Wednesday as Australia's first Indigenous member of a federal cabinet, Mr Wyatt likened a potential defeat to the setback for republicans in the failure of the 1999 referendum on an Australian head of state.

"We need to ensure that we don't go forward and fail," he said in an interview with The Sydney Morning Herald and The Age.

"It's too important in the scheme of Australian society, particularly for Indigenous Australians. To lose a referendum because we hadn't done our work properly would be a major setback for at least 10 or 20 years."

"I would rather gain something within two terms of government than to wait another 20 or 30 years before the next referendum. Often when you get burned on an issue, as we've seen with the republican referendum, people didn't vote for it, so it's never got a guernsey again. And I don't want to be in that situation."

He said the work had to be methodical and people had to be educated on the importance of constitutional change, with a rush risking a "Brexit-style reaction that sees us lose substantial gains"

Mr Wyatt, a Noongar, Yamatji and Wongi man from Western Australia, was named to cabinet in this week's reshuffle after serving as minister for aged care.

While Prime Minister Scott Morrison declared on Monday that he was "committed to getting an outcome" on constitutional recognition, he signalled caution and said the government would take "as long as is needed" to achieve a consensus.

Indigenous constitutional recognition has been on the political agenda for a decade, but attention has focused on the concept of a constitutionally enshrined Indigenous "Voice to Parliament" since 2017, when it was proposed in the Uluru Statement from the Heart alongside other key proposals.

The idea for the representative body to advise Parliament on policy affecting Indigenous people has been backed by Labor but has faced hostility in the Coalition, with senior figures describing it as a "third chamber" of Parliament. That claim has been rejected by advocates of the idea.

Mr Wyatt said the discussion was "evolving" and acknowledged people had concerns.

"Certainly, people have expressed their concern at the lack of definition and the lack of clarity as to what the Voice is," he said.

The challenge for the Morrison government is to satisfy Indigenous Australians, who were promised a referendum in this Parliament by Labor, while avoiding a fierce reaction from conservatives in the Coalition who oppose sweeping change to the constitution.

On Wednesday, Mr Pearson told the ABC that he now accepted the "reality" that the referendum proposal must be refined and advocates needed to convince people of the practical merits of a constitutional Voice.

"Its not possible to present a kind of general description of the idea for the Australian people to consider. We are going to have to articulate the full detail and I believe we can," he said.

Mr Pearson said Mr Wyatt should have three priorities in his new role: empowerment of Indigenous people, progress in closing the gap between Indigenous and non-Indigenous Australians, and working over the next 12-24 months towards a referendum on the Voice.

"If we have a voice in better policy, that will help the process of empowerment and ultimately it will contribute to the closing of the gap in the next two, three generations," he said.

MPs from both sides on Parliament's constitutional recognition committee have backed further exploration of the Voice concept and recommended a "co-design" consultation process with Indigenous communities.

Mr Wyatt flagged examination of regional bodies, noting that Labor senator Patrick Dodson and Liberal MP Julian Leeser, who have co-chaired the constitutional recognition committee, had both raised the idea as a way for Indigenous people to provide input into policy and services.

"So I want to look at that model of regional structures," he said.