'Campaign like we haven't campaigned before' Referendum campaign kicks off in Canberra

ACT representatives marked the start of the official referendum campaign at the city interchange in Canberra.

It comes as Australians prepare to head to a referendum on October 14, with Prime Minister Anthony Albanese making the long-awaited announcement in Adelaide.

Voters will be asked if they want to change the constitution to recognise First Nations Australians by establishing an Aboriginal and Torres Strait Islander Voice to Parliament and executive government.

MPs and Voice advocates from all sides of politics converged in Civic for the campaign launch day on Wednesday, including Finance Minister Katy Gallagher, former Liberal senator Gary Humphries, ACT senator David Pocock, Liberals for Yes figures and "yes" volunteers.

Senator Gallagher said the "yes" camp would "campaign like we haven't campaigned before".

"The campaign really kicks off today in earnest and we're going to work really hard right up until referendum day to make sure we maximise the vote," Senator Gallagher said.

Numerous polls in recent months have shown support for enshrining an Indigenous advisory body in the constitution has been on the decline but Senator Gallagher was optimistic Australians would vote "yes" on referendum day.

"The fact that there's not bipartisan support makes it harder but we're very, very optimistic that Australians when they engage on it, and many haven't today ... when they read the material, and they see what the proposition is, they all support a 'yes' vote," she said.

For the referendum to succeed, the majority of voters in the country and the majority of voters in four of the six states must vote "yes".

With the ACT vote only counting towards a national majority, Senator Gallagher said mobilising a high vote within the territory was important.

Senator Pocock said the referendum would be a "defining moment in Australia's history".

"The Uluru Statement from the Heart is a generous offer to all of us, not just to politicians but to all Australians, to change the way we do things when it comes to Aboriginal and Torres Strait Islander affairs," he said.

"We clearly need to change and constitutional recognition through a Voice is a way to do that, to start to address the entrenched disadvantage."

Liberals for Yes member Clare Carnell told The Canberra Times there's been a lot of misinformation around the Voice and they wanted to get the facts out to voters.

"[It's] about all of us getting out and talking to as many people as we can and then getting those people to talk to as many people as they can.

"It's game on."