Using hose pipes to wash cars or water gardens is to be banned by Thames Water from April 5 as levels fall in reservoirs across the country as the worst drought for years bites with no significant rainfall to top up supplies.

From that date it will be illegal in the Marlborough, Hungerford and Swindon areas to use hose pipes to wash cars or to irrigate lawns or gardens under the emergency measures sanction by the Government across seven water board areas in south and east England.

However in the neighbouring Wessex Water area which includes Devizes, Calne, Chippenham, Pewsey and Malmesbury no ban has yet been proposed.

Thames Water and six other companies in the worst drought-hit areas said they were imposing water-use restrictions to combat the effects of an increasingly severe drought after two abnormally dry winters in a row.

Thames, Britain's biggest water supplier, said its Temporary Use Ban (TUB) or “hosepipe ban”' would come into effect from April 5, before the Easter Bank Holiday weekend when gardeners will get busy and it and will apply to all of its 8.8 million customers.

The decision announced by the water companies on Monday comes after one of the driest two-year periods in southern and eastern England since records began. In the last 24 months the region has had 35cm less rain than normal.

The hosepipe ban follows the announcement on February 20 by Environment Secretary Caroline Spelman that South East England and parts of the East Midlands are officially in drought, and the publication on Monday day of the Environment Agency's latest drought statistics.

Groundwater levels -- the underground aquifers from which water is drawn -- across parts of the Thames Water region are close to the lowest levels ever recorded with a number of tributaries of the River Thames including the River Kennet running desperately low with stretches drying out completely for the first time in living memory.

Martin Baggs, chief executive of Thames Water, said: “We have been doing as much as we can ourselves to save water, reducing leakage by a third since its peak in 2004 to its lowest-ever level, and hitting our leakage-reduction targets five years running.

“The additional step, which we are not taking lightly, comes after two consecutive dry winters. Groundwater levels in the aquifers, which we rely on for both borehole and river supplies, are well below where we would normally expect them to be. In some cases they are at their lowest levels ever recorded at this time of year.

“We know these restrictions will be unpopular, but they will save a lot of water. A garden sprinkler uses as much water in an hour as a family of four uses in a day, and when water is in short supply the needs of families must come first.”

As well as watering gardens and washing cars the ban from April 5 will include filling swimming or paddling pools.

Gardens can still be watered and cars washed using watering cans, however.

Anyone who breaches the ban faces possible prosecution.