Data suggests the number of fixed-term deals has more than halved as prices for wholesale energy surge.

If oil prices remain high for some time, the knock-on effects could affect the costs of fuel and food

The firm was unable to cope during high demand, Ofwat says, leading to "immense stress" for customers.

It is also the first time the target has been lowered since it was cut to "around 5%" in 2023.

A trade court has cleared the way for businesses to receive refunds for tariffs that the Supreme Court struck down last month.