Ministers have bowed to pressure in a row to introduce tougher action against water companies dumping untreated sewage into rivers.
In an eleventh-hour compromise ahead of a Lords vote, it was announced a new “legal duty” would be introduced to ensure firms “secure a progressive reduction in the adverse impacts of sewage discharges” from storm overflows.
It comes after the government provoked fury from environmental campaigners and a social media backlash for voting down an amendment last week, which had been passed by peers seeking more severe action against pumping raw sewage into rivers and seas.
However, the compromise did not prevent members of the upper chamber from defeating the government on a new version of the amendment – spearheaded by the Duke of Wellington – attempting to force companies improve their sewage systems “as soon as possible”.
Members of the upper chamber voted by 213 to 60 on Tuesday evening to approve the measure, setting the stage for a Commons vote on the issue in the coming weeks.
The Department for Environment, Food and Rural Affairs (Defra) added that its alternative amendment will also be voted on when the Environment Bill returns to the Commons – but it was not immediately clear whether ministers’ efforts were enough to win over Tory rebels.
George Eustice, the environment secretary, said: “Earlier this summer, the government published a new strategy for Ofwat mandating them to progressively reduce the discharge of sewage from storm overflows in the next pricing review.
“Following a debate in the House of Commons last week during the final stages of the Environment Bill, today we are announcing that we will put that commitment on a statutory footing with a new clause.”
Hours earlier, No 10 said it “completely” agreed that is was unacceptable for water companies to dump raw sewage into the country’s rivers, but said the amendment put forward in the Lords by the Duke of Wellington was “uncosted”.
The spokesman added “the initial assessments are over £150bn and that would mean that individuals – every one of us as taxpayers – paying potentially thousands of pounds each as a result.”
Downing Street said that, as a result, “it’s not right to sign a blank cheque on behalf of customers without understanding the trade-offs and the bills that would be involved”, but “tougher legal duties” are being placed on water companies and “we will continue to listen to MPs who have legitimate concerns”.
Sewage was released into rivers and streams more than 400,000 times last year – as 84 per cent of English rivers and lakes failed to meet the government ecological targets.
There was fury when Southern Water dumped 7,400 swimming pools-worth of human waste from 17 sites in between 2010 and 2015, in what the Environment Agency called the biggest pollution case in 25 years.
Luke Pollard, the shadow environment secretary, said: “It should not have taken a public outcry for this government to take the scandal of raw sewage being discharged into our rivers seriously. Having spent the past few days defending their position, this screeching U-turn will do little to convince the public that the health of our rivers, rather than the health of Conservative polling, is at the forefront of ministers’ minds.
“The government still has no clear plan and no grip on the issue of raw sewage being pumped into our seas and rivers.”
