Fittingly, the model of the twisting, asymmetric spiral of iron was unveiled in the equally warped setting of City Hall as the Mayor of London, Boris Johnson, hailed the structure costing £19.1 million ($29 million).

He believes the 118-metres high steel construction will become a landmark to rival the Eiffel Tower, or the Statue of Liberty, which it will exceed in height by 25 metres.

Johnson said the tower, which will allow 700 visitors an hour to reach a viewing area which includes dining facilities, would help turn Stratford into "a place of destination, a must-see site on the itinerary."

He added: "I know people will say we are nuts, being in the depth of a recession, to be building Britain’s biggest ever piece of public art.

"It represents the dynamism of a city coming out of recessions.

"It is the embodiment of the multi-cultural style that makes London the capital of the creative world.

"I believe it will be a magnificent addition to the Olympic Park."

Johnson acknowledged that the design by Turner Prize-winning artist Anish Kapoor - which was chosen ahead of entries by 56 rivals including Anthony Gormley - would suggest a variety of images to onlookers.

"Some may see it as the Colossus of Stratford," he said.

"Some may see it as a convolvulus.

"Or a super-sized mutant trombone.

"Others may detect the shape of a Shisha Pipe…"

The Mayor revealed that the project, which will be completed by November 2011,  had been set into motion by a chance meeting between himself and steel magnate Lakshmi Mittel while they were retrieving their coats from the cloakroom while attending the World Economic Forum in Davos earlier this year.

"It was a 45-second conversation," Johnson said.

"I took 40 seconds to outline the idea, and Lakshmi said immediately that he would give us the steel to make it with."

Mittel will cover £16 million ($24 million) of the cost for what will be known officially as the ArcelorMittal Orbit, with the Greater London Authority supplying the balance of £3.1m ($4.7 million).

"We think that £3.1 million ($4.7 million) will be completely recouped even with the span of the Games, according to estimations by the London Organising Committee," Johnson added.

Olympics Minister Tessa Jowell commented: "What I am proudest of about this is that it is going to be a fantastic landmark that is going to be a reason for coming to the Olympic Park years after the Olympics are over.

"This is the most self-confident statement of all about the Olympic Park being a new cultural centre for London."

The structure, which contains 1,400 tons of steel, was chosen by a panel which included Sir Nicholas Serota, director of the Tate Museum, and was designed in collaboration with Cecil Balmond of engineering and design firm Arup.

"Traditionally, towers are self-supporting," Kapoor said.

"We wondered if it were possible to do something different.

"This structure seemingly works against itself - it looks like something that would not want to stand up."

Balmond added: "It’s an investigation into space, really, that’s what it is.

"It’s new."

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