Indigenous and political leaders are preparing to hold a crucial meeting in Sydney to take the next step towards recognising Aboriginal and Torres Strait Islander Australians in the constitution.

Tony Abbott and Bill Shorten pledged to take a bipartisan approach to holding the referendum, which the Prime Minister suggested could take place on the 50th anniversary of the successful 1967 vote.

The pair settled on July 6 for a meeting with about 40 key Indigenous community representatives to discuss the best way to achieve a successful outcome.

A parliamentary committee is yet to publish its recommendation for a draft question.

The committee, headed by Indigenous Liberal MP Ken Wyatt, is expected to provide a proposal by the end of June.

That will pave the way for the Sydney meeting and is likely to frame the discussion.

The Prime Minister said those who had been invited to the talks had all played a significant role in the debate.

Among those on the guest list will be Broome community leader and former chairman of the Council for Aboriginal Reconciliation Pat Dodson, Northern Territory land rights campaigner Galarrwuy Yunupingu, Aboriginal and Torres Strait Islander Social Justice Commissioner Mick Gooda, influential Cape York community leader Noel Pearson, joint campaign director for Recognise Tanya Hosch and chairman of the Prime Minister's Indigenous Advisory Council Warren Mundine.

Mr Abbott wants to "hear the views of a range of Indigenous Australians as our country contemplates change".

"The meeting will help to inform the process for deciding on a referendum proposal that will have the best chance of success," Mr Abbott said in a statement last night.

"Recognising Indigenous Australians in the constitution will complete our constitution, rather than simply change it."

Some Aboriginal leaders raised concerns the campaign to hold the referendum was losing momentum.

But the Prime Minister said the Sydney meeting would play a significant role in progressing the debate.

"This should be a unifying moment for our nation and this meeting will be an important part of this journey," he said.