Tony Abbott says early British settlement was "all bad," for Indigenous Australians, causing dispossession, discrimination and disease.

Mr Abbott made the comments last week in an interview with British newspaper The Telegraph, during his stay in Arnhem Land.

"Initially the impact [of British settlement] was all bad - disease, dispossession, discrimination, at times wanton murder," he said.

"While justice was colour-blind, there was still the enormous discrimination. There was not a lot of official respect in the early days. There was even less popular respect."

Mr Abbott said Australia had not yet come to terms with the unjust treatment of Aboriginal people and there was "discomfort in our national character" over the issue.

"Indigenous people's concerns every so often should be front and centre in the minds of our national leaders because they are, after all, the first Australians," he said.

"They were, to our discredit, ignored and at times mistreated for much of the first couple of centuries of our national existence."

Mr Abbott last week ruled out a referendum on Indigenous constitutional recognition during the 2016 federal election.

"I think it's going to be difficult to run a bipartisan referendum campaign in conjunction with a highly partisan election campaign," he said.

"That's why I don't think it is really that sensible to have the referendum at the time of the next election."

A timeframe for a referendum for Indigenous recognition is expected to be released in the next few weeks.