Mr Howard and his wife, Janette, were booked to stay at Blair House, the official White House guest house, on January 12, The Washington Post reported. The Obamas had asked to move into the mansion across the street from the White House so that their daughters could start school in Washington this week. But they were told Blair House had been booked, leading to them taking a suite at the exclusive Hay-Adams hotel instead. The White House would not say then which events were bumping the Obamas, but the Post said MrHoward's party were the only overnight visitors booked.

In 2007, Mr Howard famously attacked MrObama, then a contender for Democratic Party nomination, saying, ''If I were running al-Qaeda in Iraq, I would put a circle around March 2008, and pray, as many times as possible, for a victory not only for Obama, but also for the Democrats.''

In what was seen as an early test of his mettle, Mr Obama struck back, saying, ''I think it's flattering that one of George Bush's allies on the other side of the world started attacking me the day after I announced. I would also note that we have close to 140,000 troops in Iraq, and my understanding is Mr Howard has deployed 1400, so if he is ... to fight the good fight in Iraq, I would suggest that he calls up another 20,000 Australians and sends them to Iraq. Otherwise it's just a bunch of empty rhetoric.''

The Australians will be staying at Blair House on January 12, the night before MrHoward, former British prime minister Tony Blair and Colombian President Alvaro Uribe are to be awarded the Presidential Medal of Freedom. Mr Blair and MrUribe were also invited to stay at Blair House, but opted for other accommodation. AAP