The country’s tallest sculpture made losses of £520,000 last year despite forecasting a profit of £1.2million, according to new figures.

The report from Labour London Assembly Member Len Duvall found that the ArcelorMittal Orbit in Stratford’s Queen Elizabeth Olympic Park lost £520,000, an equivalent of £10,000 a week, in 2014-2015.

However, a spokeswoman for the park’s overseers, the London Legacy Development Corporation (LLDC), called the 200,000 visitors the sculpture has seen since re-opening in 2014 a “tremendous achievement”.

Leader of the London Assembly Labour Group, Len Duvall, said: “With the mayor’s Olympic Park Orbit tower losing over half a million pounds last year it’s clear that this is yet another Boris Johnson vanity project of towering proportions.

“Instead of paying back some of the £3million of taxpayer investment the Orbit is actually losing £10,000 a week, an awful record even by Boris’ standards.

“It looks like we can now add the Orbit to the growing list of failed Boris Johnson pet projects alongside the Thames Cable Car, Estuary Airport and fault riddled Boris Bus.”

Last year, the LLDC reduced its annual visitor forecasts for the Orbit from 350,000 to 150,000, with the latest figures showing only 124,000 visits were made to the Orbit between April 2014 and March 2015.

The report also shows that the tourist attraction was expected to generate a profit of £1.2million last year.

A spokeswoman for LLDC called the tower one of the “standout successes” of the 2012 Games.

She added: “It is establishing itself as a popular visitor destination. As with any attraction, we are constantly looking at ways to enhance the experience to attract more people to this iconic landmark.

“Hundreds of thrill seekers have already abseiled from the top of the sculpture and we’re excited at the prospect of welcoming thousands more to experience the exhilaration of riding the world’s longest and tallest tunnel slide and experiencing a new way to engage with the ArcelorMittal Orbit.

“In the coming years the stadium and Olympicopolis will be fully open and drive additional visitors to the park, many of whom will want to visit the ArcelorMittal Orbit.”