Former prime ministers Paul Keating and Tony Abbott have clashed over what Prince Charles may or may not think about Australia ditching the monarchy.
On the eve of the Commonwealth Games Mr Keating has claimed the heir to the British throne supports Australia becoming a republic and would welcome not having to "pretend" one day to be the country's head of state.
But the former Labor leader's comments have angered monarchist Mr Abbott, who has suggested it's not true.
"Prince Charles would just want to do his duty and he shouldn't be verballed by an ex-PM," the former Liberal prime minister and now right-wing backbencher posted on Twitter.
Another senior right-wing Liberal, Eric Abetz, also rounded on Mr Keating, accusing him of mounting "self-serving and egotistical" arguments for a republic.
"Mr Keating's musings clearly have no basis in fact and are just a sad feature of the latest Republican push," the Tasmanian senator said in a statement.
But federal Opposition Leader Bill Shorten said he would be "making it clear" when he met Prince Charles during his upcoming visit.
"I will be making it crystal clear that I believe it's long overdue ... that Australia has its own head of state," he said in Melbourne on Monday.
Mr Keating advocated for a republic when he led the country and used an opinion piece in London's The Sunday Times to again make that argument.
He said he had no doubt that Prince Charles believed Australia "should be free of the British monarchy".
"Why would he or anyone of his family want to visit Australia pretending to be, or representing its aspirations as, its head of state?" he asked.
He praised Prince Charles and said he'd always be welcome in Australia but added: "The pretence of representing this country and all that it stands for is something he and we could well do without."
Australian Republic Movement chair Peter FitzSimons said it would be great if Prince Charles would use his Australian tour to formally support a republic.
"We have heard that (he supports it) for many years and we don't doubt it's true," he told AAP.
"It'd be wonderful if he'd come out and say that outright, not that we have an actual expectation of that."
He also said waiting for Prince Charles to take the throne, only to ditch him as head of state early in his reign, would be unfair.
"It is very disrespectful to Prince Charles himself, and as a nation, to say we were happy with your mother reigning over us for 80 years but we don't want you at all."
Prime Minister Malcolm Turnbull, a former chair of the Republic Advisory Committee prior to an unsuccessful 1999 referendum, has previously said the issue of a republic is unlikely to be publicly debated during the reign of Queen Elizabeth.
Publicly, both Prince Charles and the Queen have stressed it's up to Australians to decide whether to follow the republic path.
Prince Charles and his wife Camilla, the Duchess of Cornwall, will be officially welcomed at a reception in Brisbane on Wednesday, before opening the Commonwealth Games on the Gold Coast in the evening.
Queensland's Labor Premier Annastacia Palaszczuk, who will greet Prince Charles on Wednesday, wouldn't be drawn on the issue.
"I'll be asking him how much he's looking forward to the Commonwealth Games," she told reporters on Monday.
