Only nine of the capital's local authorities have so far managed to identify a possible site for a flagship low-energy scheme, leaving Livingstone's target 'nearly impossible to meet.'
The revelation came from the mayor in response to a formal question from the Green Party's Darren Johnson. Livingstone confirmed that a paltry nine out of 32 London boroughs had identified sites for zero-carbon developments: Brent, Sutton, Barking & Dagenham, Lambeth, Merton, Hillingdon, Newham, Harrow and Greenwich.
The news comes just days after Olympic Delivery Authority chief executive David Higgins controversially claimed that current know-how meant there was no chance of improving on existing carbon emissions targets.
Johnson, party member for Lewisham Deptford, commented: 'It is frustrating that so few plans for zero-carbon homes have come forward from developers and local authorities.
'Zero carbon homes are the homes of the future, but the technology to build them exists now.'
He added: 'Unless London takes a lead on building zero-carbon housing now, it is going to be immensely difficult to ensure all new homes are zero carbon by 2016.'