The outage, which began on Monday, affected up to 20,000 people at its peak and SES say that supply levels are only due to be fully restored today.

It comes on the same day as the regulator is under fire for presiding over a rise in water bills– with the Liberal Democrats calling for it to be scrapped altogether.

Luke Taylor MP lobbied SES on behalf of his constituents to move further and faster to provide updates, fix the problem and provide more bottle stations in the constituency.

Luke Taylor MP for Sutton and Cheam said :

“People in Sutton and Cheam have been utterly let down by Ofwat this week.

“Many of us are paying through the nose on our water bills, only to face a major outage like this. It is not good enough and we all deserve so much more.

“SES moved too slowly in setting up bottle stations in Sutton and Cheam so that people could access water, and they clearly were not able to cope with the amount of requests for new information they had.

“Rest assured that I will be pushing for clear answers from SES on why this fault occurred, why their response has been so patchy, and why it has taken so long to be fixed.

“Whilst I’m encouraged to see forecasts that say SES bills will not rise like others, people in our area also pay Thames Water bills, which we have heard today are going to go up by £152 over the next five years overall.

“And let’s be clear – ultimately Ofwat are responsible for letting water companies off the hook on the underinvestment and bad management that led to situations like the one we face this week.

“That is why I urge the government to finally rip up Ofwat and replace it with a new, effective regulator to hold water companies accountable, and introduce a single social tariff for water bills to help eliminate water poverty.”

Latest statement from SES Water.

Morning,

We are making good progress to restore water supplies and are still aiming to return them back to normal by lunchtime today. Some customers in high rise buildings in the Sutton area may experience lower than usual water pressure and we are working hard to restore this.

As supplies return to normal, we will be taking a phased approach to close bottled water stations. As of this morning, Bourne Hall is closed while our remaining stations are open for the timebeing. Please ensure you are following our website and social media pages to ensure you are kept up to date on closures to our other stations.

Due to the nature of this incident, some customers in the following areas may notice a change in the hardness of the water they are receiving, for example increased limescale or a film on hot drinks such as cups of tea.

These areas are: Sutton, Cheam, Worcester Park, Ewell, Morden, Carshalton, Carshalton Beeches, Wallington, Chipstead, Banstead, Burgh Heath, Kingswood, Tadworth.

Meanwhile, Southern Water says a fault, which left tens of thousands of people in Hampshire with no water, has been fixed.

But it says restoring supplies will be a ‘gradual process’ to avoid bursts.

It says some customers will start to see their water supply return later today.

The environment secretary, Croydon North MP, Steve Reed, says he “shares customers’ anger” at the announcement of big water bill increases over the next five years.

Regulator Ofwat says firms in England and Wales will be allowed to hike rates by an average of 36%.