But Northern Territory Labor senator Malarndirri McCarthy has declared "the sooner the better" and said talks to set the date had taken into account the approaching wet season.
She said the logistics of travel around remote parts of Australia was a consideration because many communities can be cut off by rain in the latter part of the year.
"It's not just for those of us who are looking for the support of this referendum, it's just the practical work of the Australian Electoral Commission (and) all of their staff who have to travel out in these remote and regional places, it's tough work," Senator McCarthy said on Monday.
October 14 has been flagged as the possible referendum date.
"I reckon the earlier the better, prime minister," Senator McCarthy said.
Polling has shown increased inclination to vote 'no', with a Guardian Essential poll of 1150 people finding 47 per cent did not approve of the voice, 43 per cent were in favour, and the remaining 10 per cent were unsure.
The poll also found opponents outnumbered supporters in every state except Victoria.
This puts the referendum requirement for a majority of states in addition to a nationwide majority out of reach without a swing in sentiment.
It follows a separate Newspoll published by The Australian on Monday that showed the 'yes' case hasn't secured an absolute majority in any state.
A failed referendum would not just impact Australia domestically but potentially its international relations.
Pacific Minister Pat Conroy said the world was watching Australia's relationship with First Nations people.
He said that on diplomatic trips in the Pacific he was often asked about how Australia was advancing reconciliation with Indigenous people.
"It is important, there's an international dimension," Mr Conroy told the ABC.
"But the reason we're fighting for a voice is that it's in the interests of Australia, it will improve policy making ... that's why the voice is so important."
21°C