Ken Livingstone, mayor of London, has promised that the 2012 London Olympics will be the most environmentally friendly games ever staged.
He has just issued a new set of draft rules, to guide the construction of the Olympic facilities.
Mayor Livingstone said:
"The London games will be quite simply the most sustainable ever - leaving a lasting legacy of jobs, homes and environmental improvements for east London, London and Britain."
The new draft principles state that the facilities must meet the best design standards. Architectural competitions will be used to select the designers of the stadiums, and the other buildings, on the Stratford site.
Livingstone wants to combine the environmental record of the Sydney games, with the inner city regeneration prompted by the Barcelona games.
Bidding contractors will have to show their commitment to ethical employment practices, and use recycled materials.
£70m will be spent to bury overhead power lines on the site of the Olympic village.