A prominent leader of the ‘no’ campaign against an Indigenous voice will take the national stage and attempt to sway voters as the referendum enters the final stretch.

Warren Mundine is set to address the National Press Club on Tuesday.

New polling that shows support for constitutionally enshrining an advisory body has dropped dramatically and that the ‘no’ side maintains a majority of voters has bolstered Mr Mundine’s message ahead of his speech.

Mr Mundine has argued the voice is divisive and will not adequately represent regional and remote Aboriginal and Torres Strait Islander people.

He has however also separated from the attack lines of fellow Indigenous ‘no’ campaigner Senator Jacinta Nampijinpa Price, arguing voting against an Indigenous advisory body in the constitution would help progress treaties, something he supports.

Mr Mundine has also advocated for changing Australia Day.

Opposition Leader Peter Dutton has shut down any talk of a treaty.

But ‘yes’ campaigners remain optimistic they can secure the support of a majority of Australians in a majority of states and have the referendum succeed.

Prime Minister Anthony Albanese said despite recent polls showing a fall in support for the voice, proceeding with the referendum was the right thing to do.

“It’s always difficult to change the constitution but Indigenous Australians have asked for this,” he told radio 102.3 Adelaide on Tuesday.

“They had years and years leading up to the Uluru statement.

“Eventually, you had to give the Australian people a say and that’s what we’re doing.

“And I’m still hopeful that when people look at what the question is, it’s such a simple, gracious request.”

Mr Albanese said it would be a unifying moment if the ‘yes’ vote succeeded.

“If Australians vote ‘yes’, it will bring the country together,” he said.

“And one of the things that is occurring, though, is that we’re having a greater debate about the gap which is there between Indigenous and non-Indigenous Australians than we’ve had for 50 years.

“It’s a wake-up call for us to do something better, to do something different, and a starting point is listening to Indigenous Australians themselves.”

South Australia – a crucial swing state – has a proud tradition of showing leadership when it comes to “substantial social reforms”, Premier Peter Malinauskas said.

“It is my hope that we can do the same again in respect to the voice,” he said.

“We know that it’s not necessarily going to be easy but it’s something that we are wholeheartedly committed to at a state level, having already legislated a voice to the state parliament.”

Australians are being asked whether they want to recognise Indigenous people in the constitution by enshrining an advisory body known as the voice that will be able to make representations to the government and parliament but not hold any veto powers.

The referendum will take place on October 14.

– AAP