The sunshine state's opposition leader, David Crisafulli, on Thursday said a lot of Queenslanders would be taking their time to make an informed decision about the voice to parliament.

"I'm one of them," he told reporters.

"All I'm asking is for people to conduct themselves with civility and decency in putting across different points of view, and for people to be open-minded to the reasons that are put forward."

Federal Liberal leader Peter Dutton last week announced he would campaign for a 'no' vote in the upcoming referendum, instead favouring legislated local and regional Indigenous voices.

Mr Crisafulli joins Victorian opposition leader John Pesutto in holding off setting out a clear position on the voice.

All state and territory leaders have thrown their in-principle support behind the voice, including the sole Liberal, Tasmania's Jeremy Rockliff.

WA Liberal leader Libby Mettam has also publicly supported the proposal as has state opposition and WA Nationals leader Shane Love.

In NSW, senior Liberal MPs, including former state treasurer Matt Kean, have publicly shown support for Julian Leeser, the former federal shadow attorney-general and opposition Indigenous Australians spokesman who quit the front bench to campaign for a 'yes' vote.

Moderate federal Liberal MP Bridget Archer told ABC TV Mr Leeser's stance as an "authentic conservative" would help other conservative-minded people vote 'yes'.

Australian Associated Press