Thousands of properties in South-east England remain without water as carmaker Jaguar has been forced to halt production after multiple burst pipes across the country.
Thames Water, which has customers across London and Thames Valley, said somewhere near 10,000 properties are affected.
It provided bottled water to people as work is still underway to repair leaks that occurred after severe weather conditions.
Affinity Water, which serves parts of north-west London and the home counties, is working to restore full supply to around 1,000 properties experiencing disruptions in the past 48 hours.
Ofwat chief executive Rachel Fletcher said: “While the recent severe freeze and thaw have undoubtedly had an impact on pipes and infrastructure, this weather was forecast in advance. A number of water companies appear to have fallen well short on their forward planning and the quality of support and communication they’ve been providing, leaving some customers high and dry.”
She added they may take action after supply is restored if firms are found not to have had “the right structures and mechanisms in place to be resilient enough”.
It follows criticism from Environment Secretary Michael Gove last week, who warned water firms to clean up their act or face tougher regulation.
He told company bosses they had not been acting “in the public interest”, accusing some of “playing the system for the benefit of wealthy managers and owners”.
Chuka Umunna, MP for Streatham in south London, said he would be raising the water supply issue for his area and other parts of the UK in Parliament, while a Labour party colleague on Lambeth council tweeted a letter he said had been written to Mr Gove calling for an inquiry into Thames Water’s handling of the situation.
Councillor Mohammed Seedat tweeted: “Thames Water have shown they are not fit to manage London’s water network. Enough is enough – Jennifer Brathwaite and I are calling on the Government to step in.”
A number of schools were also unable to open due to water issues.
A spokeswoman for Thames Water said they were “grateful” to those who had heeded their low usage warning and asked for continued co-operation from customers.
Cadbury was forced to stop making chocolate due to the water shortage, and carmaker Jaguar Land Rover (JLR) has had to halt production at a car plant in central England after water supplies were disrupted by burst pipes, the carmaker and water company Severn Trent said.
A spokeswoman said the company closed its Solihull site, near Birmingham.
“Due to a water shortage caused by a burst water main, we have had to stop production this afternoon,” she said.
Severn Trent, which serves densely populated areas of central England, said that it was also facing challenges as it worked to keep schools and hospitals open.
“Due to the recent thaw we’ve experienced, our teams are dealing with a huge number of burst pipes across our region which is putting pressure on our network,” Severn Trent said in a statement. ”We’ve worked closely with Jaguar Land Rover which has agreed to stop production to help us target our supply.”
The Solihull plant is one of the Indian-owned car maker’s three vehicle production sites in Britain.
The factory employs 10,000 people and usually operates 24-hours-a-day to make cars including Range Rover and Discovery sports utility vehicles, the JLR spokeswoman said.
Meanwhile, the military was deployed to take emergency supplies – including food and fuel – to parts of Cumbria that have been left isolated following heavy snowfall that blocked roads.
Most parts of the UK are thawing out, the Met Office said, after the barrage of snow that hit the country last week.
As temperatures rise above freezing elsewhere, eastern parts of Scotland remain subject to a snow warning, meteorologist Martin Bowles said.
He said while the thaw in the South-east has been quick, the rapid rise in temperature is not unusual.
“It’s fairly quick but usually when you get a cold spell it will go up by 5 or 10 degrees in one or two days,” he said.
There are currently 28 flood alerts in place, mainly in the South-west and West of England.
Agency contributed to this report
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