Support for voice grows for first time in months

But 49 per cent intend to vote 'no' and eight per cent are undecided in a referendum which requires support from a majority of Australians and a majority of states to pass.

Prime Minister Anthony Albanese remains optimistic with 600,000 people already voting early.

"I take great heart in that, that Australians are eager to vote 'yes' in this referendum because they know that what it's about is just two things," he told reporters in Sydney on Wednesday.

"Recognition of First Nations people in our nation's founding document and secondly, about a non-binding advisory committee.

"That's all this is - to give advice on matters affecting Indigenous Australians because if you do that, if you listen to people, you get better outcomes."

A concerted effort is being made to engage Australia's multicultural communities in the referendum.

However, some have reported little to no engagement from either side of the campaign.

The Sydney Alliance, which is made up of more than 40 civil society organisations, is translating referendum material into migrant languages in the city's west, explaining how to vote. 

The alliance is also tapping into the feelings of disempowerment to explain why an Indigenous advisory body is needed in the constitution, Chantelle Ogilvie-Ellis told AAP.

The feedback from Western Sydney was relatively positive, she said.

"There's not a lot of acknowledgement of the history of Indigenous people in Australia, so a lot of our conversations are filling in that background," Ms Ogilvie-Ellis said.

The Yes23 campaign captain in the outer Melbourne electorate of Lalor said the multicultural community in Victoria's capital was equally receptive. 

The main question from migrant and refugee communities is why such a measure hasn't already been implemented and First Nations recognised, Emma Moxom said. 

"They understand what Indigenous people have been through and they've been through things quite similar," she said. 

Environment Minister Tanya Plibersek told ABC Radio National on Wednesday there was, "fantastic support from a big range of multicultural leaders". 

But some second-generation European migrants in inner-city Sydney suburbs, who did not want to be quoted, told AAP they had received almost no engagement from either side outside a letterbox drop. 

A number remain sceptical about what the voice could achieve when countless other programs have failed. 

Prominent Indigenous 'no' campaigners Warren Mundine and Senator Jacinta Nampijinpa Price have called the voice divisive and said it would split Australia down racial lines. 

"It doesn't matter whether we were here 60,000 years ago, or six months ago, you are Australian ... the problem with this divisive referendum is the fact that it seeks to create different levels of citizenship," Senator Price said.

It was this messaging that Desis for 'yes' - a South Asian-Australian run campaign - was seeking to counter, co-founder Nishadh Rajo said.

"It's really easy to spread messages like, 'if you vote this through people will take your land away or you're giving special rights to a particular group of people'," he said,

"That is why we are working so hard to spread the right information."

Australians will head to the ballot box on October 14 but early voting has begun.