Australia’s second law officer has backed the government’s wording for the Indigenous voice, advising it isn’t just compatible but “enhances the system”.

Attorney-General Mark Dreyfus released the solicitor-general’s advice on Friday, amid calls from the opposition to do so.

“The proposed amendment is not only compatible with the system of representative and responsible government established under the constitution, but it enhances that system,” the advice reads.

The advice also dismisses concerns that the voice would act as a “third chamber,” supporting the primacy of parliament.

“The voice would not form part of either the parliament or the executive government, instead operating only as an advisory body to those two branches of government. 

“The voice clearly has no power of veto.”

The solicitor-general’s comments were released as a submission to an inquiry into the voice referendum legislation.

The government plans to put the voice to a referendum later this year.

Meanwhile, fewer than half of Australians back an Indigenous voice, new polling has revealed. 

According to a Roy Morgan survey, support has fallen to 46 per cent of Australians since December.

The “no” vote had risen to 39 per cent, up by nine points, while the rate of undecided people dropped two points to 15 per cent.

Victoria is the only state in the country with a majority backing the proposal, with 52 per cent of voters in favour.

Roy Morgan chief executive Michele Levine said the ‘yes’ vote had lost support over the past months.

“The striking change since December is the politicisation of the issue,” she said.

By Tess Ikonomou and Andrew Brown in Canberra