Storey by storey ... the Shard's progress

It has been hailed by some as an architectural masterpiece, while other critics have not been so inviting.

But the Shard has been one of London's most controversial and publicised construction projects in recent years.

First designed in 2000 by Pompidou Centre architect Renzo Piano, his inspiration apparently hit him in a restaurant, leading him to sketch an iceberg like sculpture onto a napkin.

After opposition from English Heritage and the Royal Parks Foundation, the plans were approved in 2002 and construction could commence.

The Shard is now the highest tower in Europe at 310 metres high, but when Moscow's Mercury City Tower is completed later this year, it will exceed the Shard by 22 metres.

The tower will feature offices, residential apartments, restaurants, a spa, an observation deck and the 5-star Shangri-La Hotel.

The Shard is set to be completed this summer in time for the Olympic Games.