Joanne McCartney, chairman of the London Assembly's health and public services committee, said: 'It has a real problem - asking Londoners to save water while it is wasting theirs. Thames Water has missed targets three years running and the public is aware of it.'
The poster and press ads, created by M&C Saatchi, use London landmarks such as City Hall to illustrate how much water Thames Water will save over the next few years. The company has an average daily leakage rate of 894m litres.
Last week, Ofwat decided not to fine Thames Water for leakage, opting instead to revise targets and forcing it to invest an extra £150m in the replacement of aging and damaged pipes over the next five years.
'A Thames Water spokesman said: 'The overall cost of the campaign was less than 1% of the total we are spending to reduce leakage.'