The environment secretary, George Eustice, insisted the government was tackling the millions of hours of raw sewage discharges into rivers and seas in England as MPs demanded answers to a summer of water companies dumping effluent into holiday swimming spots. Caroline Lucas, the Green party MP for Brighton Pavilion, said: “Literal shit is being pumped into our rivers and seas. The state of our water network is a national scandal and the government has utterly failed to take action.” She said the government’s plan, published last week, meant sewage discharges would be permitted up to 2050. “Why is the government going backwards? “And during a cost of living scandal, floundering water bosses are still taking home obscene pay packets – pouring salt in the wounds of millions struggling to make ends meet.” Eustice said the Conservative government was the only one to tackle the problem. He said that in 2016 just 800 storm overflows were monitored but the government had increased this to 12,000 out of a total of 15,000 overflows. Using information from the monitoring had led to record prosecutions against water companies, he told MPs, with 54 prosecutions since 2015 and fines totalling £140m. Defending the plan outlined last week to reduce raw sewage discharges via overflows, which was criticised as a “cruel joke”, Eustice said: “Our discharge reduction plan prioritises bathing waters. We are requiring water companies to make available all the data on storm overflows and to publish it in real time for the public. “Water companies are investing £3.1bn to deliver 800 storm overflow improvements by 2025. We have increased monitoring of storm overflows to almost 90%, and by next year that will be 100%.” He said £56bn of investment was to be pumped into the networks to tackle the storm overflow discharges. But the government has rejected a more widespread and systematic investment to end the use of storm overflows completely. “The cost of completely removing storm overflows is around £600bn; to reduce use of them so they are not used in an average year would be £200bn,” he said. “What we have chosen to do is spend £56bn to target the most harmful sewer discharges and this will lead to significant change in years ahead … we have committed to this investment.” The investment of £56bn almost matches the £57bn in dividends the English water companies have paid out to shareholders since privatisation. As MPs debated the discharges, beaches across England were under pollution alerts once more after the dumping of raw sewage by water companies, after a night of storms and heavy rainfall. Richard Foord, Liberal Democrat MP for Tiverton and Honiton, said: “This summer, people visiting East Devon had their health put at risk by greedy water companies.” Eustice said the government was addressing the issue in the Environment Act and had given powers to the water regulator Ofwat to link dividend payments to environmental performance. Water companies should consider themselves on notice, he said. Jeremy Corbyn, the Labour MP for Islington North, said: “Isn’t it very obvious we should do what every other country in western Europe does and bring our water industry as a whole into public ownership under public control, so that we don’t damage our water infrastructure in order to pay profits to distant billionaires?” Eustice said the original vision of water privatisation was that there would be publicly listed companies on the London Stock Exchange and that water bill payers would also be shareholders. But he said: “In the early 2000s, most of these water companies fell into the hands of private equity operators and that was a change.” Also in the early 2000s, the then government took a decision to issue licences in perpetuity rather than for fixed periods. “So there have been some changes since privatisation but [Corbyn’s] central charge that actually nationalisation would be the way to get investment is, I am afraid, wrong,” Eustice said.