London mayor Ken Livingstone has made the capital鈥檚 carbon dioxide reduction targets easier to achieve, amid fears that previous standards could not be met.

Deputy mayor Nicky Gavron this week admitted that the mayor鈥檚 office had been forced to change targets for an overall reduction in CO2 emissions for the city because the government did not have strict enough regulations in place to enforce more demanding standards.

In the draft alterations to the London Plan, out for public consultation at the end of the month, the carbon reduction target is 20% of the 1990 figure by 2015. But in the mayor鈥檚 energy strategy, launched in February 2004, the mayor called for a 20% reduction five years earlier, in 2010.

Gavron said the target was taking longer than expected to achieve. She said: 鈥淲e鈥檝e changed the target to 2015. We need to make it longer because of what is available from government as regulatory backing.鈥

A spokesperson for the Greater London Authority added that it was tied to government targets. The spokesperson said: 鈥淚t has been an open secret for a while that we weren鈥檛 going to meet those targets but the government also has targets and we are tied to what it sets.鈥

In March, the then environment secretary Margaret Beckett admitted that the government was not on course to hit its 2010 goal. She said it had been 鈥渕ore difficult to meet than anyone expected鈥.

The sustainability credentials of the 2012 Olympics are also under fire, as renewable energy targets will not be met. The Olympic bid team promised that the Games would be run on 100% renewable energy, but since the athlete鈥檚 village has been moved inside the Stratford City development, it is only obliged to meet a 10% renewable target.