Jim Chalmers concedes it will be 'really hard' to convince Queenslanders on the Voice

The treasurer says it will be difficult to convince his home state to back the Indigenous Voice to Parliament.

Treasurer Jim Chalmers concedes the Yes camp faces a tough battle to convince his home state, Queensland, to back the Voice. Source: AAP / Mick Tsikas

KEY POINTS:

• Jim Chalmers says it will be 'especially hard' to get the 'right outcome' on the Voice in Queensland.
• But a key Yes campaigner insists he's confident of winning all six states.
• A Coalition senator says plummeting support for the Voice is the result of Labor's 'trickery'.

Treasurer Jim Chalmers says it will be extremely difficult to convince his home state of Queensland to vote for the Indigenous Voice to Parliament.

But a key campaigner for the Voice insists the Yes camp is confident of winning all six states at Australia's first referendum in a generation.

Prime Minister Anthony Albanese will announce the referendum date, expected to be 14 October, in the key battleground state of South Australia next week.

Polling shows support for the Voice sliding, and the Yes camp on course for defeat. Source: AAP / Bianca De Marchi

To succeed, the Yes camp needs to secure both an overall majority and a majority of voters in at least four states.

Speaking to reporters on Wednesday, Chalmers conceded his home state is "still in the balance" but described Queenslanders as "pragmatic and practical people".

"I'm confident that we can get the right outcome here when it comes to the Voice referendum, but it'll be really hard," he said.

"I think it will be especially hard in Queensland and I've never pretended otherwise."

Queensland loss would leave Yes camp with narrow path

The situation was particularly dire for the Yes camp in Queensland, where Newspoll had the No camp leading 54-39 earlier this month. It also looked all but unsalvageable for the Yes camp in WA, where the No camp was leading 52-39.

Those two states voting against the Voice would leave the Yes camp with no margin for error, and needing to pick up all remaining states.

In that scenario, one of NSW, Tasmania, SA or Victoria voting against the Voice would sink the proposal, even if an overall majority of Australians backed it.

Referendum working group member Thomas Mayo is confident of winning all six states. Source: AAP / Dan Himbrechts

And Albanese's choice of South Australia to announce the referendum date is believed to have been made with a view to shoring up support in the state, where Newspoll had the Yes camp leading 48-42.

Despite Chalmers' pessimism, Voice working group member Thomas Mayo insisted the Yes camp could "win every state".

Mayo said the Yes camp was "ready for the challenge" and was upbeat about the impact a door-knocking campaign, utilising thousands of members on the ground, would have on the race.

"We're not taking any state for granted ... We want to win six out of six states, and we're confident that we can do it with our volunteers all across the country," he said.

Sarah Henderson says Australians are being turned off by Labor's trickery and deceit' over the Voice. Source: AAP / Mick Tsikas

Albanese insists full details on how the Voice would operate will be worked through in consultation after a successful referendum.

But Coalition senator Sarah Henderson said plummeting support for the idea showed Australians were "profoundly concerned" by the government's "trickery and deceit".

"I think more and more Australians are sceptical about what the government is proposing," she said.

"The government is not being clear, and that's why we're seeing the change in the polls. But we take nothing for granted. We don't believe this is in the best interests of Indigenous Australians."