As the deadline for new bids passes, BBC Sport takes a look at the strengths and weaknesses of the nine contenders for the 2012 Olympics.
Blair may have a key role to play in London's bid
It is widely perceived that the International Olympic Committee (IOC) considers it Europe's "turn" to host.
But that in no way rules out New York, which can be relied upon to make a strong case for its selection.
London. Betting odds: 6/4
Manchester made a success of the Commonwealth Games in 2002 and that is considered a major boost to London's hopes.
Olympic president Jacques Rogge was impressed and says the English capital is the front runner.
The fact that 2012 is the year of the Queen's Diamond Jubilee may form a central part of leader Barbara Cassani's campaign.
The city was hit by confusion over the rebuilding of Wembley Stadium.
And the aborted campaign to host the 2005 World Athletics Championships - London pulled out after a row over the proposed site at Picketts Lock - also dented its international sporting standing.
Its ailing transport infrastructure could also be a big handicap.
Paris. Odds: 2-1
The French capital's accommodation capacity and transport infrastructure can cope with a huge influx of people.
World Cup 1998 was hailed as a great success and the Stade de France is already up to Olympic standard.
Some believe that the commitment displayed by the French government in staging a second bid after losing out to Beijing for the 2008 Games will go down well with the IOC.
And, if this year's World Athletics Championships are successful, Paris' hand will be strengthened still further.
Paris' poor presentation of their bid for 2008 did not impress certain parties and that may still be held against them.
And, as a result of missing out on that Games, the land set aside for the athletes' village has been given over to property developers.
In such a highly-developed city, can Paris find the room for a new village?
It is hard to estimate how long negative international reaction to the French Government's stance over Iraq will linger.
Madrid. Odds: 5-1
Madrid's status as a major European capital and its reputation as a centre of sporting passion will endear it to the IOC.
The transport infrastructure is well-funded and could cope with the demands of an Olympic Games.
The major factor counting against Madrid is Barcelona's hosting of the Games in 1992.
In Olympic terms, 20 years may be too short a period in which to award the event to the same country.
New York. Odds: 8-1
New York's unsurpassed profile gives it a real advantage, and the 11 September terrorist attacks make it the sentimental choice.
Direct US involvement inevitably makes the task of marketing the Games easier.
Vancouver's successful bid for the 2010 Winter Games is a big blow, as the IOC is less likely to back consecutive events in one continent.
The Atlanta Games were much criticised with former IOC chief Juan Antonio Samaranch significantly omitting his usual sign-off that they had been the "best ever Games".
On a wider front, criticism of American foreign policy could well count against New York.
Rio de Janiero. Odds 14-1
Its natural beauty and beaches make it comparable in some ways to Sydney, credited with a brilliant 2000 Games.
Unlike Sydney, Rio does not have a suitable infrastructure, and security poses a problem in a city whose social problems are well-documented.
Moscow. Odds: 16-1
Having hosted the Olympics in 1980, Russia believes it has the knowhow to stage the event and would just need to modernise its sports infrastructure.
President Vladimir Putin will support the bid wholeheartedly, while IOC chief Jacques Rogge could be sympathetic to a bid from the city where he was elected in 2001.
The Games would help reverse the fortunes of Russian sport, which has been in decline since the break-up of the USSR.
Money is an obvious problem and the city may not be able to match rival bids.
Security would also be a concern but Russia would argue that, given the global war against terrorism, Moscow is just as safe as anywhere else.
Russia is known for its bureaucratic inefficiency.
Leipzig. Odds: 25-1
Saw off four other cities to win Germany's nomination and will be backed by German Government.
Being a city in former East Germany carries big political weight and Rogge welcomed the bid, saying Leipzig fitted in with his plan to reduce the grandeur of the Games.
The country's two previous Games - Berlin in 1936 and Munich in 1972 - were overshadowed by politics, with the first something of a propaganda coup for Adolf Hitler and the second marred by the murder of Israeli athletes by terrorists.
Istanbul. Odds: 33-1
Steeped in history and straddling east and west, Istanbul could fulfil the IOC's ambitions to diversify.
Infrastructure and security concerns are likely to prove a huge obstacle.
Havana. Odds: 100-1
Cuba has become a track and field power and represents the Caribbean which has been the breeding ground for most of the world's top sprinters in recent years.
Fidel Castro's political regime is diplomatically isolated and with the opposition of the United States a certainty, it would be highly unlikely to get the nod.
Odds courtesy of Ladbrokes, 15 July 2003.