Water companies said they have restored supplies to most customers after days of weather-related problems as an apparently unrelated burst pipe led to more woes for a fifth day.

Ministers have announced a review into how water firms handled last week’s bad weather after thousands of homes were left without their supply.

In London, Thames Water issued a fresh apology today after a main water pipe in Tooting burst, affecting around 20 properties, most of them commercial, and forcing road diversions.

Winter weather March 7th 2018
Picture taken from the Twitter feed of @hannahwalesy showing flooding in Mitcham Road in Tooting Broadway after a water main burst in Tooting High Street, south-west London

The company said the burst was unrelated to the weather, adding that customers may have noticed a drop in pressure as a result but this was returning to normal.

A spokesman said: “We’re really sorry to customers who were affected by our burst water main in Tooting this morning.

“We worked really quickly to stop the flow of water from the pipe, which is receding, and will have a dedicated team in the area to ensure all customers are looked after.”

Elsewhere, the supplier said a large number of customers in the SW and SE postcodes had their supply back, although localised airlocks continued to affect some properties.

Industry regulator Ofwat has criticised companies for their lack of preparation, support and communication with customers, saying a number of firms “appeared to have fallen well short” on forward planning “leaving some customers high and dry”.

On Wednesday Severn Trent said all of its customers in south Birmingham should have seen their supplies restored back to normal and the company was closing two stations distributing bottled water.

Welsh Water warned of a risk of leaks and bursts as supplies were reconnected.

On Tuesday night the firm said the “vast majority” of customers whose supplies had been interrupted had been restored, although 1,000 properties in rural areas in parts of east Anglesey, mid-Ceredigion and rural Pembrokeshire were still “off-supply”.

South East Water also said some people in Sussex remained without water, although teams had reconnected restored supplies to 15,000 customers in 24 hours.

Ofwat chief executive Rachel Fletcher criticised some water companies, saying they lacked readiness and support for customers.

She said: “When the taps are back on, we will take a long, hard look at what has happened here and we won’t hesitate to intervene if we find that companies have not had the right structures and mechanisms in place to be resilient enough.”

Environment minister Therese Coffey said regulator Ofwat would be encouraged to take action “to ensure water companies up their game”.

She said a review would consider whether statutory compensation should be paid, adding that it was for water companies to consider how they can compensate customers on a discretionary basis.