Australians are almost evenly divided over a proposed Indigenous advisory body to lawmakers — known as the Voice to Parliament — that will be put to a referendum later this year, a new opinion poll showed.

Some 46% intend to vote yes in the referendum that would also see Aboriginal and Torres Strait Islanders included in the constitution for the first time, while 43% would vote no, the Newspoll survey published in the Australian newspaper showed Monday. The other 11% said they didn’t know.

Why Australia Plans to Vote on an Indigenous ‘Voice’: QuickTake

Legislation for the referendum passed the lower house of parliament last week and the newspaper said it’s the first survey to present Australians with the precise question they will be asked in the vote before December. The figures showed respondents split along gender, educational and regional lines.

The result follows federal opposition leader Peter Dutton’s decision to oppose the Voice, arguing it will “re-racialize” the constitution by giving Indigenous people rights that others do not enjoy. Australian referendums rarely succeed and when they do, they have bipartisan political support.

Still, in a major speech last week, Prime Minister Anthony Albanese reiterated that he was confident the referendum would succeed.

“Not because I am innately an optimist but because of who we have shown ourselves to be,” he said in the address. “That instinct for fairness – the great Australian instinct for the fair go that defines us – remains fundamental to our identity.”

The Newspoll surveyed 1,549 voters throughout Australia over May 31-June 3 and had a margin of error of 3 percentage points. Previous polls have shown more than 50% support for the Voice and including Indigenous Australians in the constitution.