British utility Thames Water, which supplies Cirencester and a swathe of the Cotswolds, is to spend £1.6bn for the next two years to address discharges into rivers and tackle pollution.

The announcement comes in the wake of a public backlash against UK water firms regularly discharging raw sewage during heavy rainfall into Britain's waterways.

Cirencester hit the headlines last month when singer and green campaigner Feargal Sharkey spoke out about pollution in a tributary of the River Thames at Ampney St Peter. It was revealed that sewage flowed into the river continuously for 65 hours and 10 minutes.

Sarah Bentley, chief executive of Thames Water said: "We are absolutely ramping up. I've been the first to say Thames Water's performance has not been acceptable. Sewage discharges are unacceptable. We need to make the investment."

The overall spend will be a record for the company and will include £1.12bn to upgrade sewage treatment works and sewers, given "decades of underinvestment".

Last year Ofwat served formal notices to Thames Water and others over its responses to queries on their sewage treatment operations; last week, the Environment Secretary Therese Coffey demanded water companies share plans to improve water infrastructure, warning they will face higher penalties for breaches.

Thames Water has meanwhile declared a goal to reduce its yearly discharges by 50 per cent by 2030.