Tom Calma told The Canberra Times it was "very premature" for politicians to be insisting on a detailed model for the Voice before a referendum to enshrine it in the constitution had been held.

He questioned what sort of "malice" was motivating their stance.

Professor Calma said the time for debate on the specifics would be after a successful referendum, when legislation to establish the advisory body was put to the Federal Parliament.

As the countdown begins to the referendum later this year, Peter Dutton's Liberals are demanding more information about the make-up and function of the Voice.

Opposition Indigenous Affairs spokesman Julian Leeser, who has long supported the idea of a Voice, last week warned that a lack of detail about the model would "turbocharge" the No campaign during the referendum.

Supporters including Prime Minister Anthony Albanese have rubbished the Liberals' argument, pointing to a 272-page report which sets out what a Voice could look like.

Professor Calma and prominent Indigenous academic Marcia Langton co-authored that report, which was presented to the Morrison government in July 2021.

The report recommended a 24-member panel, appointed by local and regional bodies, to advise the government and Federal Parliament on matters relating to the "social, spiritual and economic wellbeing" of Aboriginal and Torres Strait Islander people.

It would not have the power to veto legislation, deliver government programs or be a "clearing house" for research.

It would not constitute a third chamber of Parliament, as some opponents have claimed.

Mr Albanese has repeatedly referenced the Calma-Langton report when asked about a possible model for the Voice, but has stressed it would be up to the Federal Parliament to decide the specifics.

In an interview with The Canberra Times, Professor Calma endorsed that approach as he strongly rebuked the Liberals for insisting on a detailed model before the referendum.

He said the Liberals' argument was "illogical" because legislation to establish the Voice, as with most contentious bills, would likely be amended during its passage through the Federal Parliament.

"I think that they (the Liberals) should know better, politicians should know better and anybody that follows politics should know better," he said.

"What they are doing is mischievous, and you've got to ask what sort of malice is involved in this sort of practice that they're promoting."

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Professor Calma also took aim at the Liberals' junior coalition partner, the Nationals, describing its decision to come out so early in opposition to the Voice as "ridiculous".

He urged all politicians to read the report, which was based on input from more than 9400 individuals and organisations.

"(The politicians) should understand what the mood (in the community) is, and then understand that their role will come after the referendum when they debate in the Parliament what the structure will be and how it will operate," he said.

Minister for Indigenous Australians Linda Burney on the weekend laid out a rough timeline for the referendum, revealing a vote could be held as soon as August.

In an interview with the Nine newspapers, Ms Burney said the Yes campaign would launch before legislation to set up the referendum was introduced in March.

The government would aim to pass the legislation in May, paving the way for a referdum to be held as early as August or as late as November.

Mr Albanese last week declared that "momentum is growing" in the campaign to establish the Voice to Parliament.