A fresh row has broken out over the state of England's waters as the bathing season starts following reports millions of litres of raw sewage were pumped into Windermere.

Documents from water company United Utilities seen by the BBC showed that a fault at a pumping station in Bowness-on-Windermere left sewage being illegally pumped into the famous lake for 10 hours in February.

The revelations, labelled a "scandal" by opposition politicians, come as the annual bathing season kicks off with the Environment Agency monitoring 451 coastal, river and lake sites throughout the summer for water quality.

Samples are tested in labs and uploaded to the Swimfo website which updates daily with information on water quality, and provides risk forecasting information which warns people about poor water quality due to bad weather or pollution incidents.

Windermere is a popular swimming lake, with four designated bathing sites.

The latest revelations come after analysis by Friends of the Earth showed more than 440,000 hours of sewage was released along England's coastline in 2023, with thousands of spills taking place close to bathing spots.

The campaign group analysed Environment Agency data on sewage overflow outlets to calculate the number and duration of spills directly into the sea and estuaries and near swimming waters.

It found there were 68,481 incidents of sewage released into England's seas last year, totalling 440,446 hours.

More than a quarter of these, some 117,584 hours over 21,213 spills, were within 1.9 miles (3km) of a bathing spot, the assessment found.

Shadow environment secretary Steve Reed said of the news that pollution was illegally pumped into Windermere: "The Conservatives just folded their arms and looked the other way while United Utilities pumped a tidal wave of raw sewage into Britain's most beautiful lake.

"The next Labour government will put the water companies under special measures to force United Utilities to clean up their toxic mess.

"We will give the regulator tough new powers to make law-breaking water bosses face criminal charges and ban the payment of their multimillion-pound bonuses until they clean up their toxic filth."

And Liberal Democrat environment spokesperson Tim Farron said: "This is a scandal. We can't let them get away with this any longer.

"The public are rightly furious that their favourite local rivers and lakes are being spoiled while water company bosses accept huge bonuses."

He called for Parliament to accept an amendment he had put forward that could see water company bosses prosecuted for sewage pollution.

A United Utilities spokesperson said: "This incident was caused by an unexpected fault on the third party telecoms cable network in the area, which United Utilities was not notified about and which affected both the primary system and United Utilities' backup.

"As soon as we discovered this fault was affecting the Glebe Road pumping station, our engineers took urgent steps to resolve the situation and we informed the Environment Agency within an hour of the pollution being confirmed."