The federal Liberals may have spent months on the fence, but Western Australian Liberal leader Libby Mettam was quick to make clear she will not tow the party line against the national Voice to Parliament.

On Wednesday Ms Mettam told The West Australian she will be voting yes to the Voice in this year's upcoming referendum.

The state Liberal leader stated her position shortly after Peter Dutton revealed her federal counterparts would actively campaign against a constitutionally enshrined Voice for Aboriginal and Torres Strait Islander people.

"I support recognition of our First Nations people in the constitution, but I also strongly support all Australians being able to make their own decision," she said.

"Given this is a Commonwealth matter, which will ultimately be decided by a referendum, the priority must be to ensure Australians understand how the model will work at a practical level to improve the lives and outcomes of First Nations people."

The Western Australian Nationals broke ranks with their federal counterparts in November.

Then WA Nationals leader Mia Davies declared her branch of the party would support the Yes vote in the Voice referendum.

"We as a party in Western Australia have a position that is different to the federal National Party," she said at the time.

Ms Davies said her party was dedicated to ensuring "Western Australian Aboriginal people have a seat at the table".

"We want to make sure it's a structure that genuinely allows for decision-making, and authority and enhances the process we have," Ms Davies said.

Her successor as WA Nationals leader, Shane Love, has also backed the Voice.

Former Liberal New South Wales Premier Dom Perrottet threw his support behind the Voice last year, and reiterated that position again in March.

Federal Minister for Indigenous Australians, Linda Burney, said on Wednesday that Mr Dutton's position was "clear as mud".

"Mr Dutton doesn't know where he stands... Apparently, he's for a Voice, but against it. His backbenchers won't be bound by this position. That's about as clear as mud," she said.

"Mr Dutton's criticism is predictable, but despite his obsession … with the Prime Minister, this is not about politicians. This is about closing the gap, our guiding principle in this debate has been the Uluru Statement From the Heart."