Stricken Thames Water is among five water firms given the provisional go-ahead by the industry watchdog to hike bills further as part of plans allowing suppliers to spend an extra £3.4 billion.

Ofwat revealed in its draft determination that five of 13 suppliers across England and Wales are set to be given permission to increase charges for customers to pump in the additional investment by the end of the decade to help upgrade networks to cope with new housing and data centres and tackle forever chemicals to ensure drinking water is safe and reliable.

Debt-laden Thames Water is one of the firms provisionally allowed to increase customer bills between 2027 and 2030, alongside Severn Trent Water, Southern Water, Wessex Water and South East Water.

It follows a three-month review by Ofwat, with the 13 firms originally putting forward requests for further investment of £4.3 billion.

Ofwat will now consult on the draft decision until September 24 with a final verdict due in December.

Helen Campbell, executive director for delivery at Ofwat, said: “The newly agreed funding will help unlock much-needed new housing development and boost business growth across a range of sectors, as well as improving drinking water quality and the removal of PFAS and forever chemicals.

“We will track performance to ensure companies are delivering the expected improvements for customers and the environment. If they don’t, expenditure can be clawed back.”

Environment Secretary Angela Eagle said: “I know that households across the country are watching every pound and I share their frustration that years of underinvestment and toothless regulation has led to this.      “We have already ringfenced money earmarked for new infrastructure so it can only be spent on fixing the problems, and will go further by fundamentally reforming the water sector so that it works for the public; keeping bills as low as they can be, and delivering higher standards, better performance and cleaner waterways.”