Prime Minister Tony Abbott has said a referendum to recognise indigenous people in the constitution should happen as soon as possible but with the best chance of success.

Mr Abbott encouraged those calling for constitutional recognition for Aborigines to temper their ambitions and avoid rushing the process.

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Speaking at a Recognise dinner in Sydney on Thursday night, Mr Abbott said he was a strong supporter of a referendum.

The prime minister also said he would like a vote to take place in May 2017, on the 50th anniversary of the 1967 referendum.

However, he wouldn’t commit to a date until he was certain the proposal would be afforded the best chance of success, he said.

“I am prepared to sweat blood on this,” Mr Abbott said.

“But I do not want it to fail because every Australian would be the loser. It is more important to get this right than to try to rush it through.

“Nothing would set back the cause of our country and the rightful place of Aboriginal people at its heart than a referendum that failed.”

Mr Abbott also announced an additional $5 million in funding for the Recognise campaign.

Opposition Leader Bill Shorten backed Mr Abbott’s stance on the issue, saying the debate had to be void of distracting views and circumstances.

“The prime minister was right when he said we cannot allow this debate to be run off the rails by extreme views or political gain we have no time for,” Mr Shorten said.

Constitutional change must satisfy a majority of people in a majority of states.

A parliamentary committee report on the issue is due in the first quarter of next year.

— with AAP