Several water bosses will be blocked from receiving bonuses after their companies were awarded the worst possible environmental rating.
One-star ratings at Southern Water, Thames Water, South West Water and Yorkshire Water were all confirmed by the Environment Agency on Thursday.
This means they will now be blocked from paying executive bonuses as part of a government crackdown launched last year that seeks to prevent companies rewarding failure.
The latest ratings were confirmed as part of the agency's annual performance review. The best possible rating is four stars, which was only achieved by Severn Trent.
The agency announced on Thursday that pollution incidents are still far too high across the UK, with six category 1 incidents reported in 2025.
These are incidents deemed to have had a major effect on the environment or on households, and also lead to a ban on bonuses.
Both Severn Trent and Anglian Water were found liable for category 1 incidents in 2025, meaning they will also be barred from handing payouts to their bosses.
Overall, the EA found that there were 74 serious sewage pollution incidents in 2025, only slightly fewer than the 75 in 2024.
Alan Lovell, the chairman of the Environment Agency, said that the companies awarded one-star ratings had fallen "well short of the standards rightly demanded by both us and the public".
Ministers are now set to visit a number of sites to interrogate companies' performance.
Dame Angela Eagle, the Environment Secretary, said she will also be looking at options to strengthen the ban on executives' bonuses.
It follows the first ever joint report from the Environment Agency, Natural Resources Wales, the Drinking Water Inspectorate and Ofwat, which leaves nowhere for underperforming companies to hide.
In total, there were 2,666 sewage and water supply incidents that took place in 2025, with Thames Water responsible for more than any other supplier: 464.
That was down from 2,801 in 2024.
James Wallace, the chief executive of River Action, said: "Another year, another record low.
"In 2025 almost every water company in England has been ranked as performing poorly, and the sewage kept flowing into our rivers just as it has done for years.
"This year's figures show that performance is getting worse, not better."
PM vows to introduce more 'public control'
Mr Wallace said the latest pollution figures are further evidence that Thames Water, which released 108,000 hours of raw sewage into Britain's waterways last year, should be put into special administration.
The latest pollution failures have emerged despite £5bn of investment from water companies, which has pushed households' bills.
The figures come at a critical moment for the water industry after Andy Burnham vowed to introduce more "public control" over the sector.
A spokesman for Water UK, which represents the sector, admitted that improvements were needed.
He said: "Today's report shows the lowest level of leakage in history. However, the fact remains that the environmental performance of some water companies is not good enough."
Dame Angela said: "Water companies have let the public down time and time again, and today's report is further proof that root-and branch reform cannot wait.
"People are sick of excuses. I am demanding answer from the companies that are failing."
