Johnson hails London's 'astonishing' Shard tower

The tallest building in Western Europe, the Shard in London is due to be officially launched.

Simon Jenkins, Chairman of the National Trust has criticised the building, saying it is out of place and more fitting to a "banana republic".

But Boris Johnson, the Mayor of London, said it was "an astonishing piece of architecture" and that all tall buildings attracted criticism, he told Martha Kearney on Radio 4's The World at One.