Thames sewage threat to 2012 bid

London's leaders plan to "knock heads together" to stop millions of tons of raw sewage spilling into the Thames, amid fears that the pollution is jeopardising the bid for the 2012 Olympics.

Nicky Gavron, the city's deputy mayor, is to meet the Environment Agency after three giant spillages this month. Canoeists on the river are falling sick, and last week the Health Protection Agency launched an investigation into whether the pollution is putting the public at risk.

The spills are caused by "storm overflows", which release raw sewage when sewers become overloaded after heavy rain. The Environment Agency says that 36 of 57 such overflows on the tidal Thames regularly cause trouble. It has been pressing Thames Water to clean them up, but has run into opposition from the Government and Ofwat, the water regulator, which is trying to keep down water bills. As a result a proposal to build a £2bn tunnel to carry away sewage is due to be delayed for at least a decade.

This is casting a shadow over the Olympic bid - even though there are no plans to use the river for events - because the International Olympic Committee pays close attention to the quality of the environment in bidding cities.

Ms Gavron said that the problem will get worse with global warming bringing more storms to Britain. She said: "It is crucial that we solve it now, even if it means knocking heads together. The Government, Ofwat and Thames Water need to work together to sort it out."