Olympic chiefs were today accused of a "greenwash" and massively scaling down plans to make London 2012 the greenest Games ever.

Green campaigners have told the Standard that organisers have watered down their carbon emissions targets to make it easier to hit key objectives.

They now fear the ambitious plan to make the Games the greenest ever will be achieved by omitting large aspects from an audit of carbon emissions. These include the massive emissions from spectators and media travelling to and from the Olympics.

Around 200,000 people will travel from around the world to the 2012 Olympics - the equivalent to tens of thousands of tonnes of carbon.

Campaigners say that without these emissions the measuring exercise would be cosmetic "greenwash". They are also concerned that developers have started construction on venues without targets for reducing emissions being set.

Olympic bosses admitted a key report detailing calculation of London 2012's carbon footprint has been delayed - raising fears authors are struggling to work out how to make the Games the greenest so far.

Darren Johnson, a Green Party London Assembly member and chair of its environment committee, said: "We need a full audit, not a watered-down greenwash exercise."

But the London Organising Committee of the Olympic Games said its groundbreaking report had been delayed to ensure the calculations are the most accurate possible.