Jun 19, 2009, 11:07 GMT
Japan's Crown Prince Naruhito is the "ace" in Tokyo's bid to host the 2016 Olympics.
The city's governor and bid committee president Shinataro Ishihara has asked the 49-year-old royal to travel to an International Olympic Committee meeting in Copenhagen in October to strengthen his campaign.
Ishihara was initially planning to recruit the nation's 75-year-old emperor Akihito, but opted for Naruhito and his wife Princess Masako because of the ruler's recent poor health.
He said: "It is too difficult to ask the emperor Akihito to come because of his age and health, but our next ace is to ask his eldest son, the crown prince, and the crown princess. I have asked the prime minister to make this official request."
Tokyo last hosted the Olympics in 1964. It will compete against Chicago, Madrid and Rio de Janeiro for the 2016 Games.
IOC rules allow heads of state and other dignitaries to attend the Copenhagen session, where the cities will make their final presentations and IOC members will vote.
US President Barack Obama, Spain's King Carlos and Brazilian President Luis Ignazio da Silva are expected to attend the meeting.
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