Robert Booth of The Guardian reports: London's mayor, Ken Livingstone, has launched a vision of a green future for the capital with buildings shrouded in lush vegetation, populated by wildlife and powered by hydrogen, not fossil fuels. His "blueprint for a sustainable London" attempts to make London the world's most sustainable city and could see developments refused planning permission unless tough new environmental targets are met.

Mr Livingstone wants renewable energy sources incorporated into all new buildings and developers to soften the hard edges of their structures with hanging gardens, roof gardens and bird boxes to keep buildings cool and draw wildlife into the city.

The initiative comes amid growing frustration at national efforts to improve the sustainability of Britain's buildings which are estimated to account for half of greenhouse gas emissions. A survey of architects revealed that half believe conditions for sustainable building have got worse under Labour. Last week protesters from Greenpeace stormed John Prescott's house and installed solar panels to protest against the lack of progress made in using renewable energy.

Under Mr Livingstone's proposals, at least 30% of construction materials should be sourced from within 35 miles to reduce transport pollution, and the mayor wants housing developments to recycle or compost over a third of their waste by the end of the decade.

His plans have been labelled "radical" by sustainability experts and "on another planet" in comparison with government policies.