The Mayor has defended London's rapidly changing skyline after concerns the capital is being overdeveloped.
Figures show more than 200 buildings of 20 storeys or more could be given the go-ahead over the next few years. Supporters say they'll provide much needed housing, but critics are worried it will radically alter the city forever. Our Political Correspondent Simon Harris has this report.
Mike Dunn, the Principal Inspector of Historic Buildings at English Heritage, said the results of the survey should ring alarm bells.
"They can overshadow historic buildings, they can overshadow whole historic areas, they can fundamentally change London's familiar skyline and it is something which needs to be managed very carefully."
Mr Dunn added that some of the new skyscrapers were appearing in areas where historic views aren't protected by current guidelines.
"The areas that we are seeing huge numbers of tall buildings aren't in those areas which are currently well-protected by that view management framework, areas like Vauxhall, Nine Elms.
"I think we're getting huge walls of development at the moment."
London is in the middle of an unprecedented skyscraper boom. A new survey reveals another 236 high-rise buildings could soon appear on the capital's skyline.
The disclosure has promoted renewed concern about the impact on historic views of London. The survey was carried out by a design think-tank called New London Architecture. The figures suggest the boom is being driven in part by London's housing crisis.