The Assembly’s environment committee urged Thames Water to ensure customers get “good value” and do not ask them to “pay over the odds”.
The Assembly is concerned about the impact of any potential increases on Londoners, claiming the recession and its aftermath has affected the capital significantly.
It said that if the bill increase were to be approved, the impact should be spread over a period of a few years to minimise any difficulties that Londoners have in managing the increased cost.
The Assembly also called for Ofwat to publish guidelines on debt management in a bid to “ease the burden of bad debt on paying customers and support those with genuine difficulties”.
Murad Qureshi, chair of the London Assembly Environment Committee, said: “Many Londoners are already struggling to cover bills amid cost of living increases, so we welcome Ofwat’s draft decision to turn down Thames Water’s bills increase application.
“As the domestic water market is a monopoly in each area, the role of the regulator is crucial in protecting the customer. Ofwat must continue looking closely at the case made by Thames Water to ensure Londoners aren’t asked to pay more than they should. ”