LONDON BRIEFING:The city is hoping its mayor's fumbling of the Olympic flag is not a portent of trouble ahead.

THE WORLD watched with some amusement as London mayor Boris Johnson struggled to unfurl the Olympic flag at the closing ceremony in Beijing at the weekend. In Britain, however, the audience was praying that the fumbling over the flag will not be a portent of things to come.

Spirits here have been hugely lifted by our athletes' stellar performance, the best in 100 years. But, even before the jubilant Olympians returned home with their haul of medals, the enormity of the task facing the nation's capital in four years' time was finally starting to sink in.

London has 1,430 days left to prepare itself for the next Games; a tough task made even tougher by having to follow what was arguably the most spectacular and best-organised Games.

Scores of officials from the London 2012 team went out to Beijing to watch how the Chinese did it, including former Olympic medal winner Lord (Sebastian) Coe, who heads up the organising committee for 2012.

The London Games will be very different, not least because of the capital's £9.3 billion budget, only a fraction of what the Chinese spent. Johnson insists that the budget will not be exceeded, a pledge that most observers find hard to take too seriously.

Indeed, as he returned to London yesterday, Johnson was regaling reporters with a "wonderful moment" from the closing ceremony - "When Sebastian Coe turned to me after about five minutes and said: 'That's half our budget gone'."

Apart from the very real fear that the Games will come in neither on time nor on budget, one of the biggest concerns is whether London's congested roads will crack under the strain of the huge influx of traffic.

Transport for London has suggested special Olympic lanes be used by athletes and officials only, with the public relying solely on public transport. But the plan is controversial and, say its critics, risks plunging the capital into gridlock as the world watches on.

Johnson, or "Bumbling Boris" as he is known, has been in office for a little over 100 days. He enjoyed some early wins, recruiting a team of experienced and respected advisors. But his administration appears to be unravelling at a rapid rate, with the abrupt departure of some of his highest-profile appointments.

Private equity supremo Tim Parker, aka "The Prince of Darkness", was brought in to tackle administration waste and, many believed, effectively to run the capital. Having made his fortune turning round Clarks Shoes, Kwik Fit and the AA, Parker accepted his role as deputy on a nominal salary of £1 a year.

But he quit last week, a shock departure which followed the exit of Ray Lewis, brought in to spearhead Johnson's ambitious plans to tackle youth crime. Lewis quit amid allegations of "inappropriate" behaviour and financial irregularities, while a third advisor, James McGrath, exited ignominiously in June after suggesting in an interview that immigrants from the Caribbean should go home if they did not like Boris's London.

Barclays' Bob Diamond, one of Britain's best-known bankers, downgraded his role at City Hall after just six weeks. Diamond was recruited to help run the Mayor's Fund for underprivileged children but, although he remains an advisor, he will no longer play a central role as initially planned.

Diamond, who heads Barclays' investment banking arm, was the only key advisor to be named ahead of Johnson's election and his recruitment boosted Johnson's credibility in the City.

Parker is perhaps the biggest loss to the administration. Although his appointment was controversial, particularly because of his track record as a "slash and burn" manager, Parker would have played a key role.

As one observer put it, the plan was for Parker to run London "and for Boris to put the bubbles in the champagne".

Now, amid tales of power struggles and backbiting, Johnson finds himself taking on rather more of the hands-on management of London than he had ever planned. For someone who has admitted being useless at business, that is a daunting prospect, even without the massive challenge of preparing the capital for 2012.

If Bumbling Boris manages to get through the next four years with his administration - and London - intact, then perhaps the first medal of the 2012 Olympics should go to him.

Fiona Walsh writes for the Guardian newspaper in London