BRITS must stop using tap water for gardening and washing cars, the water watchdog says.

Ofwat boss Rachel Fletcher urged families to use recycled bath water and rainwater instead, warning that climate change and a growing population posed a threat to water supplies.

She also called for an increase of water butts in gardens.

The watchdog chief told MPs: “As a sector we need to think about transferring water from one region to another.

“And we have got to shift the frontier in the technology used to deliver supplies.

"The idea of using treated drinking quality water on gardens and to wash cars in the 21st century just doesn’t seem appropriate.”

Severn Trent has asked homeowners to be “neighbourly” about consumption, with a spokesman saying householders should limit their use at peak times.

Environment Minister Therese Coffey urged people to cut down on long showers.

She said: “It is actually a big use. Every little bit helps in trying to reduce the consumption of water.”