Prominent Indigenous elder Noel Pearson has issued a call to arms for supporters of the voice, saying more work needs to be done, with the referendum's success in doubt.
Support for constitutionally enshrining an Indigenous advisory body has been tracking downwards according to numerous polls.
Mr Pearson said the 'yes' campaign had its work cut out but "the inertia is no, the momentum is yes".
"The 'yes' campaign has got to get out, it's not going to fall into our laps," he told Sky News on Sunday.
"We need to be at the railway stations, we need to be at the town halls, we need to be meeting people in the malls and we need to be appealing to the better angels of the Australian nature."
Former Australian Labor Party president Warren Mundine, who is campaigning against the voice, said it would be hard for the 'yes' campaign to shift the momentum, with polling showing Australians are against enshrining it in the constitution.
Mr Mundine said while the public wanted practical outcomes, the government was failing to make the case for how a voice would deliver change on the ground.
He said education and economic participation, such as starting a business and getting a job, were key to closing the gap.
"What we have got to do is focus on the people who do need help," he said.
Mr Pearson said a 'no' vote would be devastating for reconciliation and leave Australia "in the darkness".
"Every time we've come to this issue, we've been on the default setting of 'no'," he said.
"Look at all the outcomes from having that 'no' setting, 30 per cent of people in prison comprised by three per cent of the population being Indigenous.
"Juvenile justice, 40 per cent of our kids comprise children in detention."
Deputy Liberal Leader Sussan Ley said the constitutionally enshrined voice would create an "unnecessary bureaucracy" but she supported a legislated model that focused on local communities.
"I would like to see a legislated voice with that local approach," she told ABC's Insiders program on Sunday.
"The voice is important in the way that it may close the gap and the way it may improve the lives of Indigenous people"
Ms Ley added she didn't want "one national body coming out of Canberra but a voice that comes from each community".
Mr Pearson hit back at accusations the body would be Canberra-centric and stacked with metropolitan elites.
"People see me as a national kind of figure that has got an influence and they say, 'Oh, could you please advocate this issue for me?'
"I'm responsible for Cape York ... I can't do it for you.
"If we had a system where their own leadership was able to interact with the government in a productive way, you'll see change in those places."
The clause pertaining to making representations to government has also stirred controversy, with conservatives warning it would enable the body to lobby for changing Australia Day.
But Mr Pearson said the voice would only make representations on issues that affect Indigenous people with talk about nuclear submarines and parking tickets "lurid misrepresentations".
"Who's going to listen to them if they say we need dot dot paintings on the side of the new nuclear submarine," he said.
He added that politicians in a democracy are lobbied by all sides of politics and various interest groups on a constant basis.