A key architect of the Indigenous voice has panned a proposed change to how it interacts with parliament.
Attorney-General Mark Dreyfus suggested adding a phrase to the constitutional change to ensure parliament decided on "the effect" of the voice's representations.
Referendum working group member Thomas Mayo described the addition as "unnecessary and not desirable".
"The frustration is that we're possibly months away from a referendum and now we're having a debate about some extra words," he said.
"It's nation building, it's unifying, it's a fair thing to do.
"It's recognition of over 60,000 years of continuous culture before, you know, colonisation."
The working group will gather in Adelaide on Thursday before releasing its final advice.
South Australia's deputy premier and Indigenous affairs minister will address the group about their state-based model for a voice.
The Labor state government is hoping to have its legislation passed by Easter.
Indigenous Australians Minister Linda Burney said she was looking forward to hearing what lessons could be learnt.
"We want to build on the strengths of the South Australian model and make sure Indigenous communities have their voices heard," she told AAP.
Legislation to set up the referendum will be introduced to federal parliament by the end of this month, while a second bill will outline the question to be put to Australians at the national vote, which will take place later this year.
