The group was created to put pressure on the water company in light of pollution and flooding concerns. It features representatives from more than 24 local authorities, including Adur District Council and Worthing Borough Council cabinet members, that aim to act as a collective public voice.

Whilst the councils don't have the power to directly regulate Southern Water, by working together as the Southern Water Stakeholder Group they hope to apply enough pressure to force the company to address its list of local failings.

At its most recent meeting, members of the group told Ofwat managing director Paul Hickey that Southern Water, which was also in attendance for the meeting, had failed to deliver promised upgrades and took too long to respond to issues.

Mr Hickey pledged to better support the councils, following criticisms that the watchdog has not been effective in holding Southern Water to account.

He added that its fundamental duty is to ensure that customer and environment interests are met, but that it was keen to have evidence in advance about concerns so it could hear from the water companies how those issues could be addressed.

As the national regulator for the water sector, Ofwat’s duties include ensuring that water companies properly carry out their statutory functions and protect the interests of their consumers.

Cllr Steve Neocleous, Adur’s cabinet member for regeneration and strategic planning, said: “We still have our concerns over Southern Water and its attitude towards protecting our coastal waters and rivers, not only for the benefit of our residents but the ecosystems and wildlife that rely on these spaces being clean.

“In addition to this, we also have concerns about the ability of the existing infrastructure to cope with the cumulative effect of new development. We are looking for Southern Water to provide more reassurance on this.

“I hope we can continue making progress as a collective through the meetings.”

Cllr Vicki Wells, Worthing’s cabinet member for the environment, said: “It was fantastic that Ofwat took our concerns on board.

“As local authorities, we constantly encounter the ‘pass the buck’ culture when trying to resolve water related issues for residents. This has got to stop. Southern Water and ultimately regulators, including Ofwat, have got to work more effectively with local authorities to address the issues that impact water quality and the environment.

“Ailing infrastructure, excessive rainfall and poorly maintained natural waterways need the collective, efficient participation from all stakeholders to deliver the improvements needed locally and regionally.”

The stakeholder group recently called on Steve Barclay MP, Secretary of State for Environment, Food and Rural Affairs, to improve funding for the Environment Agency needed to help enforcement against failing water companies.

The next meeting of the Southern Water Stakeholder Group will be held in the spring.