Thames Water discharged raw sewage into rivers nearly 5,028 times last year, campaigners have claimed.

Data analysed by the Oxford Rivers Improvement Campaign shows that the company dumped more than 68,000 hours of untreated water into the River Thames and its tributaries, including the River Windrush, Evenlode and Ock.

An Ofwat spokesperson told ELN: “We share the concerns of the public. The current levels of storm overflow discharges into rivers cannot continue and the water sector must tackle this.

“Ofwat recently called on all water and wastewater companies to prepare plans setting out immediate steps they will take to reduce overflows and improve river quality.

“We also have an ongoing investigation into all companies on how they manage their sewage treatment works.”

Andy Prendergast, GMB National Secretary, said: “The massive sums paid out to water bosses and shareholders must instead be invested in our rivers and waterways and improving services for consumers, including a pay rise for the water workers who are leaving the industry in droves.”

A Thames Water spokesperson told ELN: “We’ve received the report and will be looking at it carefully in the coming days. Our aim will always be to try and do the right thing for our rivers and for the communities that love and value them.

“We regard all discharges of untreated sewage as unacceptable and will work with the government, Ofwat and the Environment Agency to accelerate work to stop them from being necessary and are determined to be transparent.

“We recently launched our river health commitments which include a 50% reduction in the total annual duration of spills across London and the Thames Valley by 2030 and within that an 80% reduction in sensitive catchments.

“We have a long way to go – and we certainly can’t do it on our own – but the ambition is clear.”