The head of Thames Water has said customers should expect their bills to go up next year as the struggling supplier upgrades its ageing infrastructure. Joint-interim CEO Cathryn Ross made the warning as she faced MPs at an Environment Food and Rural Affairs Committee meeting on Wednesday. It comes as the UK's biggest water company - serving 15 million people in London and South East England - is fighting for its future amid a £14 billion mountain of debt, while facing higher interest rates due to inflation. Report by Jonesia. Like us on Facebook at http://www.facebook.com/itn and follow us on Twitter at http://twitter.com/itn