COPENHAGEN, Denmark (Reuters) – American First Lady Michelle Obama arrived yesterday, the first of a succession of state dignitaries due in Copenhagen to promote four rival bids for the 2016 Summer Olympics ahead of tomorrow’s IOC vote.

The First Lady, who will be joined by her husband President Barack Obama tomorrow when `they become part of the team presenting Chicago’s bid for the Games to the International Olympic Committee, will lobby IOC members over the next 48 hours.

Also due in yesterday were Brazilian President Luis Inacio Lula da Silva, backing Rio de Janeiro, and King Juan Carlos and Spanish Prime Minister Jose Luis Zapatero, supporting the Madrid bid.

Newly elected Japanese Prime Minister Yukio Hatoyama, who is promoting Tokyo’s cause, will also be in the Danish capital.

Michelle Obama said nothing to the waiting media at Copenhagen Airport before she was whisked into the city centre for a series of bid-related meetings.

Her husband will become the first sitting U.S. president to address an IOC session and the most high profile of a succession of leading political figures, including then British Prime Minister Tony Blair four years ago, and then Russian President Vladimir Putin two years ago, to successfully campaign for London’s 2012 bid and Sochi’s 2014 Winter bid respectively.

Obama’s visit is widely seen as a high-risk strategy with the potential gain of helping win the bid for Chicago weighed against serious political fallout should the Windy City fail.

The 2016 contest has been declared too close to call by most Olympic observers though Obama’s presence has made Chicago a marginal favourite.

On the second of three days of intensive lobbying in Copenhagen, the bid cities were turning to sporting heroes to promote their cause.

Rio brought in soccer great Pele. “Everybody knows my life. I won a lot of tournaments and scored more than 1 000 goals, won three World Cups but I could not play in Olympic Games,” he told reporters. “Sometimes I still think I did not get that gold medal.”

Chicago had Olympic and world champion athlete Michael Johnson, leading a fun run through the streets of Copenhagen, to back their bid.

Japan’s 2000 Olympics marathon gold medallist Naoko Takahashi was also making an appearance in support of Tokyo.

Slowest out of the blocks was Madrid who have held no media events and stage their first news conference this evening, only 36 hours before the IOC session begins.