'I think as sure as I stand here Australia will become a republic,' Mr Keating told reporters. 'It's not a matter of if but when and I think that the royal family probably comprehends that.'
Over the next 12 days, Prince Charles will come under pressure to enter the republican debate from the ordinary Australians he meets on his travels through New South Wales, Tasmania, Western Australia and Queensland. He is due to make a speech in Sydney tomorrow to mark Australia Day, the anniversary of British colonisation 206 years ago.
Mr Keating has nominated Australia Day in 2001 as the target date for a republican referendum. But Prince Charles's mission is apparently designed to steer attention away from republicanism and to restore the standing of the monarchy, undermined in Australia by a vigorous republican debate which Mr Keating launched two years ago, and by scandals in the royal family.
Prince Charles will be followed by a British media contingent of 42 on his first Australian tour since his separation from the Princess of Wales. The Australian media, and Buckingham Palace, will be watching the visit closely for signs of the Prince's impact on the republican movement.
The Prince's itinerary complies with his wishes that it embrace Australian youth, Aborigines, disadvantaged people, environmental restoration, health and ethnic groups. The formal receptions of previous visits, attended by establishment figures, have gone.
Prince Charles may take heart from the latest opinion poll on republicanism, published last month in Time, that showed support for the monarchy had increased 10 points to 48 per cent. Australians for Constitutional Monarchy, a group of prominent figures defending the Crown, argue that this shows Australians are having second thoughts about ditching the Queen.
The Australian Republican Movement sees it differently. Andrew Johnson, a movement spokesman, said yesterday: 'There have been nine major polls in the past year, and we have won them all except this one. This visit seems to be more relevant to Britain than it does to Australia, where the cult of the monarch is rapidly waning.' He said the republican movement had surveyed the youth wings of all Australian political parties and 15 student leaders, all of whom supported a republic.
Having broken the ice by explaining his republican policies to the Queen at Balmoral last September, Mr Keating is likely to feel more relaxed during his meetings with Prince Charles. The two men share a strong interest in architecture, and Mr Keating has invited the Prince to attend a meeting on Friday of the Task Force on Urban Design, which he established last year.
Asked by British journalists in Sydney yesterday if he was excited by the impending royal visit, Mr Keating replied: 'Not half as excited as you seem to be.'