How much, who's paying and the key players

The budget has been the most controversial aspect of preparations for the London Olympics. It was originally costed at £2.4bn during the bid, with around £1bn extra for "regeneration" purposes. After the bid was won it became quickly apparent that the budget was inadequate in March 2007 the Government confirmed it had jumped to £9.3bn. The budget breaks down as follows:

Key costs:

* Security - £600m
* Venues - £1.17bn, including:

Stadium - £525m
Aquatics centre - £242m
Velodrome - £80m
Olympic village and media centre - £496m
Olympic Park preparation and infrastructure - £1.942bn
Other park costs (eg site security) - £868m
Transport - £897m
Contingency fund - £2.7bn

Contributors

Central government - £5.975bn
National Lottery - £2.175bn
Greater London Authority - £925m
London Development Agency - £250m
Total - £9.325bn

Who is in charge?

The Olympic board is the key decision-making body within the 2012 project and comprises the mayor, the Olympics minister, the chairman of the 2012 organising committee and chairman of the British Olympic Association. It meets monthly and the chair alternates between the Government and the mayor.

Colin Moynihan, chairman of the BOA

The former Olympic rowing cox and Tory sports minister was elected chairman of the BOA when Sir Craig Reedie - a key architect of the 2012 project - stood down after the bid. Moynihan recently shaken up organisation to help it meet the challenges of hosting the next Games. Under Moynihan the BOA - whose main task is sending teams to the summer and winter Games - has targeted an unprecedented fourth place at 2012 with around 700 athletes - more than double the size of the Beijing squad. Former England Rugby coach Sir Clive Woodward was chosen by Moynihan to help turn potential into gold medals. The BOA is searching for a new chief executive to boost its fund-raising activities and will move premises in the New Year, probably nearer to the Stratford site of the Games.

Tessa Jowell, Olympics Minister

Convinced the cabinet under Tony Blair to back an Olympic bid after witnessing the success of the 2002 Commonwealth Games in Manchester. Jowell's formidable networking skills and relations with former mayor Ken Livingstone were crucial to the bid win. Moved to the Cabinet Office as Olympics minister in Gordon Brown's first re-shuffle. Jowell is one of the few key figures remaining from the bid and has insisted that the £9.3bn budget will not be exceeded despite warnings to the contrary.

Sebastian Coe, chairman of the 2012 organising committee

Arguably the most influential member of the board, given his connections across Westminster and in the world of Olympic sport. Coe has used his political cunning to keep at a distance from budgetary rows while his team have earned praise from the IOC for progress on the event management side of the project. Most dear to him will be creating the legacy of a sports infrastructure in Olympic events which the capital so badly lacks. As a vice chairman of the International Association of Athletics Federations, he is expected to run for the top job in 2011.

Boris Johnson, Mayor of London

Johnson made cost-cutting at City Hall one of the key pledges of his election campaing and he has used the Olympics to highlight this. His 2012 supremo, the Carphone Warehouse boss David Ross, has warned that the £9.3bn budget may overrun but he has advised he mayor that major projects cannot be reversed to cut costs. Critics say that the Ross report said nothing new, but the mayor insists it has been important in creating more transparency around Games planning, especially the budget.

How we won the Olympics

When the London bid was launched by Tessa Jowell and then bid leader Barbara Cassani in the spring of 2003, few gave it any chance of success against front-runners Paris and Madrid.

Factors counting against London were thought to include withdrawal from hosting the athletics world championships at Picketts Lock and the war in Iraq.

After Cassani made some key appointments, she stood aside a year later for Seb Coe who turned out to be the perfect ambassador for a 2012 Games.

The race for 2012 was considered Paris's to lose and London exploited this. The Paris campaign was conservative bordering on complacent whereas London's was eye-catching.

It appealed to the International Olympic Committee's wish to attract a younger following and offered financial incentives to athletes from poorer nations.

At the vote in Singapore, the campaign was boosted by the star quality of David Beckham and the one-to-one appeals to IOC members by Tony and Cherie Blair.

On July 6 Madrid were knocked out in the third round of voting and their backers transferred votes to London in its head-to-head with Paris. But it was close - London won by 54 votes to 50.