The opposition party leader travelled to Oxfordshire on Friday to launch a campaign targeting what he called a concealment of sewage data by water companies.

Fresh statistics from the government indicate that England recorded 291,492 individual sewage overflow events throughout 2025, yet those responsible for water services are not required by law to monitor or reveal the actual amounts of waste discharged.

The party is calling on regulators to mandate that water businesses quantify and make public the volumes of sewage being dumped, claiming this would help communities better appreciate the environmental damage occurring.

During his stop in Eynsham, the party leader met with Ash Smith, the campaigner whose investigations into hazardous sewage releases prompted the recent Channel 4 documentary series Dirty Business.

The Liberal Democrats have been pushing ministers to place the financially troubled Thames Water into special administration.

According to the leader, this situation constitutes a nationwide disgrace. Simply knowing how long a sewage release lasted fails to provide adequate information about the true scale of destruction. While company executives receive generous payouts and customers face rising bills, ordinary households must deal with contaminated rivers and streams. The party demands an end to this secrecy and insists the full extent of the problem be revealed.

Records show that Thames Water diverted more than 19 million cubic metres of sewage away from the River Thames beginning in August 2024.

The utility also expressed regret for a water service failure that left large parts of Reading without supply during the night.

The company is negotiating terms to prevent temporary government control after building up roughly £20 billion in liabilities, bringing it to the brink of collapse.

According to a Thames Water representative, the firm is working to minimise overflows to improve river conditions. Over the next five years, the largest wastewater system overhaul in a century and a half is underway, including upgraded treatment facilities, reduced storm overflows, and new pollution reduction programmes. Protecting river ecosystems remains crucial, and transparency regarding data is vital to achieving this. The current monitoring infrastructure across the water industry fails to record sewage volumes, with measurements only conducted where permits specifically require them. Flow monitoring equipment has been installed at Mogden, Didcot, and several key combined overflow locations in London to assist with major infrastructure projects. Any available volume data is published for public access.

Thames Water maintains that special administration would hinder advancement for consumers and the natural world, creating instability, increasing costs, and making operational recovery more difficult without addressing the underlying financial problems.