The Liberal Party have confirmed their MPs will convene on Wednesday in a special party room meeting to discuss their position on the Indigenous Voice to Parliament referendum.

It comes as the shadow attorney general and shadow minister for Indigenous Australians, Julian Leeser, told reporters he blamed the government for failing to engage the Australian community on the Voice to Parliament, saying the Labor Party had "tunnel vision" and was "mucking it up".

"The government needs to ask themselves that there is enough support the moment to put the referendum, that's the question need to ask themselves," he told the National Press Club on Monday.

Mr Leeser confirmed the Liberal Party will meet on Wednesday to decide a position on the Voice but warned a "completely concluded position" may not be reached, despite the long delay to date in the Liberal Party getting off the fence on an issue of historic national importance.

"I don't think people should assume that we will have a completely concluded position on things on Wednesday," he said. He also said a vote on the issue would be unlikely.

"It is rare things come to a vote in the party room. Usually things are worked through, people have their say and a consensus is arrived at."

Former federal minister for Indigenous Australians and Liberal MP, Ken Wyatt, urged his party to allow all members to vote freely on the subject.

Mr Wyatt, a Yamatji man who was the first Indigenous Australian to be elected to the House of Representatives, said a conscience vote is needed and he hoped they would endorse "Constitutional recognition of The Voice".

He noted that previously he stated he knew many in the party would back the Voice "if given the chance," he was also aware that many in the party were strongly opposed.

"I'm also conscious in my time within the party there are many who don't hold that view at all in fact strongly oppose it," he told Sky News on Monday.

"I would hope that the leadership would give members a conscience vote. I'd just say to the leadership: allow a conscience vote to allow this country to move forward."

Shadow Minister for Community Safety, Migrant Services and Multicultural Affairs, Jason Wood, has previously backed a conscience vote and has been contacted by National Indigenous Times for comment.

Mr Leeser disagreed with Ken Wyatt's assertion that a failure to offer bi-partisan support to the voice would give credence to the "globally" held view that the Liberal Party is "racist".

"I've got great respect for Ken Wyatt. But there are reasons to have pause in relation to this referendum that have nothing to do with race and everything to do with the constitutional structure of our government and the failure of process," he claimed.

In his speech on Monday, the shadow Attorney-General highlighted three changes to the proposed model that he wanted enacted.

These include support for "local and regional voices;" funding them in the May budget, a call for bi-partisan legislative consensus before a referendum, and a reconsideration of the wording; particularly the clause which mentions the voice will make presentations to the executive.

Constitutional experts have rejected suggestions the Indigenous advisory body would be too powerful, calling it a "safe and sensible" legal option.

In response to Mr Leeser's speech, the Prime Minister told reporters in Adelaide, "I say if not now, when?".

"Indigenous people expect this to be advanced," he said.

"That is why we need to get this done, and to not put it to the Australian people is to not advance it, is to, by definition - if you don't run on the field you cannot win. You cannot succeed."