The South Australian opposition will vote against legislation to allow for an Indigenous voice to state parliament.
The government's proposed bill was tabled earlier this month and is likely to pass with support from crossbench MPs.
But opposition Aboriginal affairs spokesman Josh Teague said it was rushed and defective and in isolation would do nothing to improve outcomes for Aboriginal and Torres Strait Islander people.
"Labor's bill completely ignores existing engagement methods, which could and should be better utilised and instead deliberately steers clear of those longstanding bodies," Mr Teague said.
"The legislation will essentially create a third chamber of parliament allowing the body to address the house on any issue."
Mr Teague said the government's model would be expensive to establish, with the elected representatives supported by a separate government bureaucracy, the size and nature of which was unknown.
He said the Liberals would oppose the bill in its current form but might look to make amendments.
The legislation proposes regions with directly-elected representatives be established around SA.
Two members from each group would then form the State First Nations Voice, which could address either house of state parliament on particular legislation of interest to Aboriginal people, provide reports to parliament and engage with ministers and department chief executives on budgets and priorities.
Those elected to regional groups and the state body would serve a four-year term, in line with state parliamentary terms.
Following community consultation, a number of changes were made including the establishment of specific committees representing young people, elders, native title holders and members of the stolen generations, to advise the State First Nations Voice.
Provisions were also made to ensure the voice did not affect native title agreements or other Indigenous organisations.
Aboriginal Affairs Minister Kyam Maher said the legislation was a defining moment for South Australia.
"Long-overdue recognition of our state's first people and an acknowledgement that we can do more to listen to their views," he said.
