Peter Dutton claims the proposed Indigenous voice to parliament will take the country backwards, labelling it a reckless roll of the dice and an "overcorrection".
But as Mr Dutton argued the body would divide the country, Indigenous Australians Minister Linda Burney accused the opposition leader of stoking division.
Federal parliament has begun debate on the Indigenous voice, ahead of a referendum to enshrine the body in the constitution later this year.
"Changing our constitution to enshrine a voice will take our country backwards, not forwards," Mr Dutton told parliament on Monday.
"The voice is regressive, not progressive. Our constitution is not something to be toyed with lightly."
A bill on the voice will finalise the wording that would be placed in the constitution, should the referendum succeed, and the question that will be put to voters.
Mr Dutton reiterated his previous criticism of the voice proposal, arguing there was not enough detail, and claiming it would permanently divide the country by race.
"It will have an Orwellian effect where all Australians are equal, but some Australians are more equal than others," Mr Dutton said.
"This referendum on the voice will undermine our quality of citizenship. It's an overcorrection.
"If the government wants you to vote on a voice not knowing what it is or what it can do, the approach is a reckless roll of the dice."
Debate on the voice in parliament follows the release of a parliamentary committee report on the bill, which recommended it pass without changes.
The Liberals support constitutional recognition for Indigenous people but in the form of a legislated body for regional voices, rather than a national entity.
Mr Dutton has been accused of shoring up a misinformation and scare campaign.
"In 2023, it is time for recognition. It's time for an Aboriginal and Torres Strait Islander voice to the parliament, because (they) have not enjoyed the same opportunities of so many other Australians," Ms Burney told parliament.
"Constitutional recognition through a voice to the parliament is about giving Indigenous Australians a say in matters that affect us. It means delivering structural change."
The process to establish the voice had not been rushed, Ms Burney said, and had been developed over many years with the support of Indigenous people and outlined in the 2017 Uluru Statement from the Heart.
While concerns have been raised about the voice being able to advise "executive" government, Ms Burney said the approach was the right one.
A vote on the bill is expected to be held in the lower house next week, before debate shifts to the Senate.
The referendum is due to be held between October and December this year.
Nationals leader David Littleproud said the voice would not adequately address the issues facing Indigenous people in regional areas.
"It will create another taxpayer-funded level of bureaucracy in Canberra. A nation needs a better bureaucracy, not a bigger one," he told parliament.
But Liberal MP Bridget Archer flagged her intention to support the voice, arguing it would be more than just a symbolic body.
"This referendum provides an incredible chance to begin writing so many wrongs and to bring about tangible differences in quality of life outcomes for Aboriginal and Torres Strait Islander people," she said.
"Most Australians agree that the status quo isn't acceptable and that as a country, we must do better. Here's our chance."