Your article "Mayor gives zero-carbon scheme green light" (3 February) is wrong to suggest that I have not been implementing my energy strategy.

We have taken significant strides forward in achieving an increase in the amount of renewable energy and energy efficiency measures in new developments. I have introduced and supported the development of four groundbreaking pilot Energy Action Areas across London, which will be using renewable energy technologies. All Greater London Authority buildings are supplied by green electricity tariffs except the London Development Agency and London Fire and Emergency Planning Authority, and I have asked them to achieve this target by the end of the financial year 2006/07.

The LDA will shortly be moving to new offices, where it will be looking at buying renewable power along with the integration of significant renewable energy-generating technologies. The London Fire and Emergency Planning Authority is committed to ensuring a proportion of its energy needs are provided from renewable or low-carbon sources. Schemes have already been completed at Richmond and Tooting fire stations and more are planned.

Ken Livingstone, mayor of London