Water suppliers face a fresh wave of scrutiny from the industry regulator after thousands of homes were left without ­water in the wake of sub-zero temperatures across the UK.

Ofwat will launch an investigation into how water companies responded to the “Beast from the East” storm system after they were fiercely criticised for failing to safeguard the network against the freeze.

Rachel Fletcher, Ofwat’s new chief executive, said the regulator would “get to the bottom” of why thousands of people were left without water for days.

“We’ll find out where companies did well by their customers and where they’ve fallen short, including the compensation being offered to those who were directly affected,” she said.

Water pipes across the country were left badly damaged after the freezing conditions gave way to a sudden thaw, which split and cracked them, disrupting the water supply to thousands of homes and businesses.

At its peak around 20,000 homes were cut off in the South East and north London. Jaguar Land Rover and Cadbury both agreed to shut their manufacturing sites to preserve water for households.

Ms Fletcher fired a warning shot last week in which she said that several ­water companies had “fallen well short” in their duty to prepare for ­extreme weather.