THAMES Water is hoping to increase bills up by an average of around £100 to pay for infrastructure improvements.

If approved, bills will increase by one per cent above inflation for five years from 2015 while another £70 or £80 will be added to pay for the Thames Tideway Tunnel.

It is part of a review of current price rules which have been agreed with the regulator Ofwat.

Thames Water spokesman Natalie Slater said: “We propose that by 2019-20 our average household bill will be £370 a year before inflation, up from £354 today.

“This excludes the cost of the Thames Tideway Tunnel, which is to set result in a maximum bill impact of £70-80 a year by the early 2020s.

“Our customers' bills are the second-lowest in the country, at less than £1 a day per household, while we continue to invest a record £1bn a year in infrastructure upgrades – more than any other company ever has.

“As a result, Thames Water's operational performance – as measured by leakage, tapwater quality and sewage works compliance – is close to its best level ever.”

The Thames Tideway scheme is a proposed 25km tunnel running underneath the River Thames through central London due to be completed in 2022.

It will store and transport raw sewage and rainwater which currently overflows into the river.