Noel Pearson has coached grassroots 'Yes' campaigners to effectively advocate for the Voice to friends, family and wider community.

On Thursday, the Cape York Indigenous leader, activist and architect of the Uluru statement spoke to social justice and poverty prevention organisation Brotherhood of St Lawrence with advice on mobilising support for a Voice to Parliament.

BSL officially endorsed a 'Yes' vote last week.

Earlier on Thursday, Mr Pearson told ABC RN "We're not going to fail" despite falling support for the proposal in polls.

"This is the most important vote in two hundred or something years of European presence in Australia. It is simply the most important vote we will ever have," he said.

"We are the generation that finally has the opportunity to settle this question (of recognition)."

"The recognition has to be substantial, practical. It has to have an impact for the better on the lives of Aboriginal Torres Strait Islander Australians, to close the gap, to reconcile.

"It's not just a symbolic acknowledgement in the constitution."

Speaking that afternoon, Mr Pearson said the Voice is the vehicle to allow First Nations people prosper.

"I can't see how we can (prosper) without recognition and dignity. We will make little progress. We'll make about the same progress we've been making today. Which is not good enough," he said.

Rheumatic heart disease, Closing the Gap, housing and the increased cost of living - which Mr Pearson said has hit Aboriginal and Torres Strait harder, were highlighted as areas a body in government and constitutional recognition would help positively shift.

"You live in a remote community…you are doing it very hard," Mr Pearson said of cost of living.

For BSL, he said the Voice would provide an ally in their means to alleviate poverty across Australia.

"Tackling poverty, by definition, is Closing the Gap," Mr Pearson said.

In conversing with the community to spread this message, Mr Pearson called for the reminding others not to "sit on their hands".

He said the Voice proposal is not a political debate or opportunity to "vote for your favourite team" amid official stances taken by major parties.

Three months out from the referendum, Mr Pearson is confident of turning "soft noes".

"Let's not set unrealistic expectations that everybody's going to completely comprehend with constitutional arguments to-and-fro. The real question is, what are we doing? What are we doing with this?," he said.

"My answer to that is we are achieving recognition. How are we doing it? We're doing it through the Voice…and why are we doing it? Because we want to achieve reconciliation."

Mr Pearson said the Voice will be a "beautiful" thing to give children to read in the Constitution.