Water fountains could be put up in parks and public spaces across London under plans being developed by Boris Johnson.
The Mayor believes that providing free water for Londoners would help deter them from buying plastic bottles. He has instructed special adviser Sir Simon Milton to look into where the drinking fountains could go and how much they would cost.
Mr Johnson said: "If this place is generally getting hotter and people are going off buying bottled water I think we should have a new era of public fountains."
The move would be a major victory for the Evening Standard's Water on Tap campaign. Hundreds of restaurants, cafés and clubs are already willingly providing customers with free tap water. The campaign aims to end the practice of offering expensive and environmentally damaging bottled water without mentioning it is available on tap.
A spokeswoman for Mr Johnson said: "The Mayor is keen to see more drinking water fountains on the streets of London to help reduce the use of bottled water, the use of which causes unsightly litter and unnecessary waste."