The coalition supports amending the constitution to formally recognise indigenous people but Opposition Leader Tony Abbott hints it could take some time.
"I am supportive of a referendum (on the issue), but we've got to get the right proposal," he told reporters in Sydney on Tuesday.
"That's going to involve a lot of careful discussion."
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Mr Abbott has given bipartisan support to the referendum idea, which Labor committed to earlier in the week as part of its effort to "close the gap" between indigenous and non-indigenous Australians.
But Mr Abbott said it was merely a reannouncement of a commitment Labor made in 2008 and did not act upon.
Former prime minister John Howard signalled support on the issue back in 2007, he said.
"It's very important that we should appropriately acknowledge the place of indigenous people at the heart of modern Australia.
"On the other hand, we've had a lot of symbolism over the past couple of years.
"We've now got to get on with making a difference."
Getting the right proposal for a referendum could take a bit of time, Mr Abbott said.
"The last thing we would want would be to put a proposal of this nature to the people and have it fail."
