By Kat Wong and Tess Ikonomou in Canberra

VOTERS have continued to turn against an indigenous Voice to parliament with overall support sliding to new lows and every state except Tasmania poised to vote “no”.

The most recent Resolve Political Monitor survey, published in Nine newspapers on Monday, showed 43 per cent of voters supported a plan to enshrine an indigenous Voice into the constitution, down 20 percentage points from a year ago.

The percentage of Australians in favour of the referendum has dropped for the fifth month in a row and since the last survey Victoria has flipped to a majority “no” state, leaving Tasmania the only jurisdiction left in the “yes” camp.

For the Voice to succeed, the “yes” campaign will require more than 50 per cent of the vote across the nation and in four of the six states.

Asked about the falling support, Environment Minister Tanya Plibersek said there were still many undecided voters who could be convinced.

“We’re going to ask them to vote ‘yes’ because this acknowledges 65,000 years of Australian history,” she told Seven’s “Sunrise” on Monday.

“This idea came from Aboriginal people, well over 80 per cent of them support it. This is not a committee that has a veto over parliament. It doesn’t stop things happening.

“It is a committee to give advice, it really is a lot less scary than some of the ‘no’ campaign are making it out to be.”

Independent senator Jacqui Lambie said the government had “failed miserably” in its bid to sell the positives of the voice and provide detail.

“Labor’s done a really lousy job at selling this, to be brutally honest,” she told Sky News.

But she also rejected the opposition’s pledge to hold a second referendum on constitutional recognition as a “brain fart”.

Nationals leader David Littleproud said the prime minister needed to split the question to avoid dividing the nation, with most people supporting constitutional recognition of Aboriginal and Torres Strait Islander people.

He denied a failed referendum would send a negative message to indigenous Australians.

“The message is that Australian people have come and they’ve decided that the proposition the prime minister has put forward to us isn’t the proper way to unite our country or to actually close the gap,” Mr Littleproud told reporters in Canberra.

“Many indigenous Australians feel that view now and that’s why I think it’s wrong for indigenous leaders who support ‘yes’ to… make generalised statements about how indigenous Australians will feel.”

Postal vote applications open on Monday and close on October 11.

The electoral roll closes seven days after writs are issued – meaning people have a week to ensure they’re enrolled.

Hundreds of early voting centres will be available from October 2, with centres to open in the ACT, NSW, Queensland and SA a day later due to a public holiday.