Southern Water bill increases of 91 per cent have been dubbed "grotesquely unfair" by opponents who fear the worst-off in society will be affected.

The water company has announced plans to charge households an average of £915 per year by 2030, the biggest increase in the country.

It said it needs more money to bring costs in line with inflation and to invest in infrastructure.

The Argus: Southern Water's head officeSouthern Water's head office (Image: The Argus)

Lewes Liberal Democrat candidate James MacCleary has taken Southern Water to task in recent years over its track record of spilling untreated sewage.

He told The Argus: "Water, sewage disposal, these things are not optional. We can't go to an alternative provider like our broadband or TV and there is a competitive market.

"It is Southern Water or nothing, so for people on low incomes already struggling, they are now facing almost a 100 per cent increase in their bills. It seems grotesquely unfair.

"Income tax is at record high levels and we are expected once again to subsidise these record-high profits."

The Argus: James MacClearyJames MacCleary (Image: Liberal Democrats)

Bills this year are around £420 and were around £436 in 2014, which would approximately £582 today when adjusted for inflation.

James, who is also a councillor in Newhaven, called on more people to take a stand against the water companies.

"As someone who pays for this myself, it makes me really angry," he said. "In my community there are people struggling day to day to afford their weekly shop and then there are Tory MPs and others who think it is completely reasonable to expect these people to pay nearly 100 per cent more on their bills for a failing service."

It comes just weeks after tens of thousands of homes in Hastings were without water for four days after an ageing Southern Water pipe burst.

It was also revealed that Southern Water dumped 317,285 hours worth of sewage into waterways last year - equivalent to 36 years.

Read more: Southern Water vows to stop pumping sewage into village pond... by 2030

In 2021, Southern Water was fined a record £90 million by the Environment Agency for illegally dumping water into the sea.

People took to social media to voice their concerns. Warren Bennett said: "Why do we just sit back and keep getting mugged off by these greedy con men.

"We've become a nation of whingers with no intention of action. We should all refuse to pay our water bills until the leaks are fixed, they stop dumping sewage into the sea and stop paying out dividends to their shareholders."

The water company already provides a 45 per cent discount on bills to more than 120,000 customers - with this number expected to rise to 200,000 by 2023.

The Argus: Sewage spilling off the coast of Seaford in 2022Sewage spilling off the coast of Seaford in 2022

Southern Water's chief customer officer Katy Taylor said: “The figures being reported are loosely based on the bill rise proposals we put to Ofwat during the development of our draft business plan for 2025–30.

"Ofwat decides the charges our customers should pay, based on what we’ve proposed to deliver in our plan to meet regulatory requirements."

The water companies will meet regulator Ofwat this week, where it will decide how much they will be allowed to charge customers between 2025 and 2030.

Ms Taylor added: "While we await confirmation from Ofwat on our plan and the correspondent increase in bills, the numbers quoted have been increased by a third party to take into account estimated inflation levels over the next six years.

"We share everyone’s concerns about rising payments in the face of a cost-of-living crisis. We have been able to keep bills low, with the average combined water and wastewater bill increasing by only £2 in the past ten years in nominal terms.

"We agree with our customers that we must now charge more so we can bring our bills in line with inflation, rising costs and, more importantly, so we can invest more to meet the expectations of our customers, and protect and enhance our environment."