Following pressure from the Green Party, Ken Livingstone has admitted the London Development Agency (LDA)
is a long way off delivering even a single zero-carbon development in the capital.
to see a zero-carbon scheme in every one of London's 33 boroughs by 2010.
The news comes just days after the government was slammed for reneging on its Kyoto promises and will further damage Livingstone's reputation as a keen supporter of the environmental cause.
It is almost two years since the mayor promised to back a wave of flagship carbon-free schemes across the capital as part of his high-profile Energy Strategy for London.
However, there is still no sign of the first project emerging - a lack of progress that has not surprised eco-architect Bill Dunster, who designed high-profile sustainable housing scheme BedZED. He said: 'We don't know of any zero-carbon schemes coming through and we have been trying to get the LDA to do one for years.'
Dunster believes there is now 'no chance' of the mayor hitting his 2010 target for carbon-free buildings.
He said: 'The biggest things are the cost and the lack of will. 'The LDA is sitting on vast amounts of land, so they clearly have the capability to do this. It's up to them - it's not through the lack of opportunity.
'Zero carbon is just not coming through as a priority and they just can't get the surveyors to release their grip on their remit to maximise land values.'
Admittedly a more expensive approach - at least initially - Dunster feels the only way to make zero-carbon schemes affordable is by building somewhere between 2,500 and 5,000 units a year.
And he believes the commitment to such projects is wanting. He added: 'We went to the London Borough of Newham and offered them a scheme for 4,500 zero-carbon homes and they didn't want it.'
Darren Johnson, leader of the Green Party in the London Assembly, was also disappointed by the mayor's response. He said: 'We know that there was originally a clear aim to promote zero-carbon developments.
'There are some pretty good policies in the London Plan but they are not being systematically pursued in new planning applications.'
And Catherine Harrington, of environmentally conscious practice Architype, called for immediate policy reforms. She said: 'The government should be taking decisive action on reducing London's substantial environmental footprint.'
It appears this pressure has had some effect on the mayor.
According to a written statement from Livingstone, he has asked his office to 'start discussions with the LDA about an exemplary zero/low emission development'.