It will be the first time an American President has attended an International Olympic Committee (IOC) vote and lobbied in person for a US city to become host of the Games.
 

Obama had initially claimed that the pressing issue of health care reform would prevent him from making the trip to Copenhagen and he rang the IOC President Jacques Rogge to tell him that he would be sending his wife, the First Lady, Michelle Obama, to represent him.

But there were signals last week that Obama was likely to make the trip after all, and the White House sent an advance team to Copenhagen to prepare the way.

The final decision was made public early this morning in Washington that he will travel to the Danish capital on Thursday, 24 hours before the vote at the IOC Session on Friday.

Chicago organisers were naturally delighted at his decision, which could prove decisive to them being elected ahead of rivals Madrid, Rio de Janeiro and Tokyo.

Chicago Mayor Richard Daley said: "President Obama and First Lady Michelle Obama symbolise the hope, opportunity and inspiration that makes Chicago great, and we are honored to have two of our city’s most accomplished residents leading our delegation in Copenhagen.

"Who better to share with members of the International Olympic Committee the commitment and enthusiasm Chicago has for the Olympic and Paralympic Movement than the President and First Lady."
 

The Chicago bid leader, Patrick Ryan, said he was honored that Obama would join the bid team "for the pinnacle moment in our bid."
 

Obama is expected to be a part of that final presentation.

Obama and his wife will join a large delegation that will be in Copenhagen, including more than two dozen Olympians and Paralympians. Oprah Winfrey, Education Secretary Arne Duncan and Transportation Secretary Ray LaHood also will make the trip.

The other three candidates will also be bringing their most senior officials.

Brazilian president Luis Inacio Lula da Silva will be part of the Rio team, King Juan Carlos of Spain will back Madrid's bid and newly elected Japanese Prime Minister Yukio Hatoyama will support Tokyo.

It was the decision of then British Prime Minister Tony Blair to travel to Singapore on the eve of the 2005 IOC Session to lobby on behalf on London for the 2012 Olympics that was widely credited with helping them beat Paris, who were the favourites.
 

At the next vote to choose a host city, in 2007, Vladimir Putin, who was then President of Russia and is now Prime Minister, addressed the IOC membership in Guatemala City in English, the first time he had spoken it in public, pushing successfully for the resort city of Sochi, to host the 2014 Winter Olympics. 


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