THAMES Water customers in Oxfordshire could be forced to help foot the bill for a multi-million pound sewer improvement scheme in London.

The company is planning to build the Thames Tunnel, running 20 miles from west to east London, to help prevent 39 million tonnes of sewage a year from entering the river at 14 overflow points.

This could cost customers in the county an additional £65 a year on their water bills from 2013.

Simon Evans, a spokesman for Thames Water, said a planning application for the Thames Tunnel could be submitted in 2012.

And he confirmed that customers in Oxfordshire and Gloucestershire could be forced to pay an additional £65 per year.

Pensioners’ spokesman Bill Jupp, 79, of Arlington Drive, Marston, said: “This is worrying for pensioners who rely on a state pension and have a fixed income.

“Utility bills have been increasing in recent years and so has the cost of a weekly shop.

“This is the last thing we need and I would urge Thames Water to limit the increase to Londoners.

“People in Oxfordshire pay enough for their water and I don’t see why we should subsidise this scheme in London.”

Mr Evans said the increase could start in 2013 and “reach a peak” in 2018.

He added: “London has a Victorian sewerage system. Thames Water bills have been among the cheapest in the country for the past 20 years.

“Part of the reason for that is that it is much cheaper to serve London’s dense population than it is other areas, so it is only fair that bills should be shared across our region.”

Simon Markall, a spokesman for water industry watchdog Ofwat, said: “Thames Water’s final plans on the Thames Tunnel are yet to be finalised.

“This includes the costs. We are scrutinising their proposals and working to ensure that costs are kept as low as possible.”