Free tap water for visitors at all venues during Games

Paul Deighton, chief executive of the London organising committee, said it will "ensure the provision of free drinking water to the public at Games venues".

The move is a further triumph for the Evening Standard's Water on Tap campaign, which has persuaded more than 3,000 London bars and restaurants to offer free tap water to customers.

Liberal Democrat MP Tom Brake said today it was a breakthrough in making it socially acceptable to offer tap water everywhere. "This is a major victory in a London-wide campaign led by the Evening Standard to have free water on tap," he said.

"But we need to maintain the pressure on the organising committee and check through all the long building process if they really install free drinking water fountains." Organisers admit they are still unsure how the water will be delivered.

Mr Deighton added: "The mechanism for providing this may vary from venue to venue depending on the type of infrastructure available and we will be reviewing this matter as we advance through our planning processes."

Mr Brake also raised questions over the drinks suppliers signed up as major sponsors to the Games.

He said: "Worldwide sponsors of the 2012 Olympics have huge financial interests in selling their products on the sites.

"I have planned several meetings with all the official sponsors to discuss with them how to keep our Olympics green."