Malcolm Turnbull says a referendum on Indigenous recognition and a plebiscite on same-sex marriage won't be held on the same day.

The prime minister is working with Indigenous leaders and the opposition leader to come up with a referendum question and an amendment to the constitution, and has promised a national vote on changing the Marriage Act.

"They certainly won't be on the same day, I can assure you of that - they are two separate issues," Mr Turnbull told reporters in Brisbane on Friday.

This announcement came as Mr Turnbull unveiled $115 million in grants to help go-getting Indigenous Australians take a leap into corporate Australia and build on the skills learnt under the Community Development Program.

Opposition leader Bill Shorten followed suit by announcing that a future Labor government would spend $200 million over five years on doubling the number of Indigenous people employed as rangers to help manage land in remote areas of Australia.