Acrobats abseiled down Nelson's Column for the first time ever as London re-lived its 2012 Olympic victory.

The aerial performers made history as they descended the world-famous landmark, unveiling a 300ft silk banner of the London 2012 logo as they went.

And former M-People singer Heather Small also entertained the crowd packed into Trafalgar Square for the event as a second banner reading 'London Prepares' was unveiled.

Mayor of London Ken Livingstone said: "Today we are showing London, the UK and the world that preparations for the 2012 Olympic and Paralympic Games are under way.

"The passion and commitment we put into the bid is now carrying through to delivering what will be the greatest Olympics ever.

"I have already directed the London Development Agency and Transport for London to do everything necessary to ensure there are no delays in our planning and a contractor has now been selected to remove and reroute the power lines and pylons that cross the Olympic site."

London 2012 Chairman Sebastian Coe added: "We said we would start work straight after the decision, and these were not empty words.

"In the first six days after the decision, 17,000 people registered an interest in volunteering for the Games, with the total tally standing at nearly 60,000 people today.

"Eight days after the decision, the Olympic Bill was introduced to Parliament. Twenty days after the decision, the first lottery scratchcards were launched to fund the Games. Although it will take a few years before we see the actual venues, much work will be done preparing the site."

The Trafalgar Square spectacular also marked the start of "Everyone's London" a new month-long campaign of great events, attractions and experiences highlighting the very best London has to offer.

The 100-plus events, festivals and special days out that are happening throughout September will be complemented by a series of major promotions including offers through West End theatres and across London's Underground.

"Everyone's London" will culminate in truly historic style as Oxford Street closes to traffic for the first time for a day-long street festival.