Water bosses have been told by ministers they will no longer “mark their own homework” on whether they are illegally polluting rivers, in a shift in how the sector is regulated.

The number of hours in which sewage was dumped into the River Thames has more than quadrupled in the last year, figures show.

There were 6,590 hours of sewage spills in the last nine months of 2023, according to the data from Thames Water, analysed by London's City Hall. It is up from 1,420 hours for the same period in 2022.

Campaigners say 76% decline in riverfly species’ abundance at Cunsey Beck is being caused by sewage discharges.

Labour says consumers are facing higher bills while water bosses rake in millions in bonuses - despite rampant sewage dumping. Water company bosses have received over £25m in bonuses and incentives since the last general election.

Nine chief executives of water companies have been paid a staggering amount despite dumping sewage in rivers, lakes and seas, according to research by the Labour Party.

Water bosses responsible for illegally dumping raw sewage “should be in the dock” for the damage caused to the UK’s waterways, Labour’s Shadow Environment Secretary has insisted.

Lake Windermere is a UNESCO World Heritage site but the flow of sewage from nearby rivers has become a grave concern.

Over 36,000 people have signed a petition calling for a public inquiry into Lake District fish deaths.

Save Windermere launched the petition last year claiming that the Environment Agency’s investigation into the death of the fish at Cunsey Beck was not fit-for-purpose and its conclusion that it would not take any action on the incident was not sufficient.

The Environment Agency failed to visit 90 per cent of toxic water spills last year, including more than 60 per cent of the most serious incidents. There has been a major drop off in in-person inspections of water pollution incidents since the Covid-19 pandemic, with the Environment Agency failing to attend most cases.

The amount of work needed to make Windermere sewage-free has been revealed for the first time. The Save Windermere campaign, led by Matt Staniek, has called for all sewage outputs in the lake to be removed similar to Lake Annecy in France.

Fiona Marley Paterson covers United Utilities drop-in sessions on ITV Border and questions United Utilities over sewage spills seen on the same day at Ferry House WwTW.

Like Greta Thunberg’s first climate strike five years ago, Matt Staniek’s first “sewage strike” was a low key affair. While setting up a folding table outside a water firm’s office in Windermere last week, a bypasser stopped by. “Hey mate, I support ya, but you’re causing a health and safety issue there,” he told Staniek.