Flood water threatens the town of Upton-upon-Severn Enlarge Image

Up to 350,000 people in Gloucestershire will be left without running water by Monday evening, as the Severn and Thames rivers threaten to overflow.

The Environment Agency said water levels on both rivers had exceeded those of devastating floods in 1947.

Prime Minister Gordon Brown said he would set up a review of the crisis.

Mr Brown flew by helicopter over Gloucestershire, the worst-affected county, before heading to the police headquarters where the emergency response is being co-ordinated.

The review would look at drainage and flood defences, while extra funding would help pay for essential emergency work in the aftermath of the crisis, Mr Brown said.

Floods: At-a-glance Your stories of the floods

The Environment Agency said water levels on the River Severn at Gloucester could peak early on Tuesday, while the level of the Thames in Oxford may not peak until early on Wednesday.

Severe flood warnings are in place for the Midlands, Oxfordshire and Bedfordshire. At their height, some rivers will be more than 20ft higher than normal.

Environment Agency spokesman Anthony Perry said: "We have not seen flooding of this magnitude before. The benchmark was 1947 and this has already exceeded it."

In March 1947, millions of pounds of damage was caused in the south of England, the Midlands, East Anglia and North Yorkshire when many rivers burst their banks.

Other main developments include:

• Environment Secretary Hilary Benn told the House of Commons the emergency was "far from over" and further flooding was "very likely". An independent person would head the flood review announced by the prime minister, he confirmed.

• Environment Agency chief executive Baroness Young told the BBC that about �1bn a year was needed to improve flood defences.

• The Association of British Insurers has said the total bill for the June and July floods could reach �2bn.
• The RAF said it is carrying out its biggest ever peacetime operation, with six Sea King helicopters rescuing up to 120 people.
• More than one hundred Royal Navy personnel have been sent to Gloucestershire to help the worst affected areas.

Severn Trent Water warned all residents in Gloucester, Cheltenham and Tewkesbury - an estimated 350,000 people - would lose their supply by Monday evening due to a treatment works being flooded.

The situation is expected to last several days, it said.

No electricity

Gloucestershire County Council said bottled water was being provided and a number of water bowsers being deployed to the area.

Cherry Lewis sent in this picture of Lybrook, Gloucestershire

Elsewhere in Gloucestershire, 15,000 homes are still without power after a major electricity substation at Castlemeads was turned off because of the rising water.

Electricity supplier Central Networks has advised customers to ring 0800 328 1111 to report loss of supply.

Over the border, parts of Worcestershire were under 6ft of water and the Army has been deployed to help emergency services provide supplies to people in Upton-upon-Severn.

Richard Myers, a butcher in the town and a volunteer for Mercia Inshore Search and Rescue Service, said he had been rescuing people from bedroom windows.

"This is the worst I've ever known it," he said.

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The Bishop of Worcester, Dr Peter Selby, said: "It is rare for a disaster of this kind to affect so much of the country at once, and my prayers are with everyone in the affected places at this difficult time."

Warwickshire and Berkshire have also been badly affected and severe warnings remain in place for Oxfordshire.

Residents at risk of flooding in Oxford have been told to leave their homes as water levels are expected to rise.

Some homes in Oxford, Abingdon, Kidlington and Bladon have already been flooded and conditions are expected to deteriorate.

'Critical' situation

Meanwhile, the government has rejected calls to stop building houses on flood plains, despite the recent extensive flooding.

A draft of the Housing Green Paper, which was obtained by the BBC, says it is "not realistic" to rule out new developments in areas at risk of flooding.

The Environment Agency has issued eight severe flood warnings and says the situation is "critical".

There are four in the Midlands for the River Avon and River Severn between Worcester, Tewkesbury and Gloucester.

HAVE YOUR SAY We must now look at proper regional controls and answers for surface water problems Ted Smith, Worcester Send us your experiences

Three severe flood warnings are in place for Oxfordshire, from Eynsham to Abingdon, and one has been issued for the River Great Ouse from Turvey to Sharnbrook in Bedfordshire.

The heaviest rain is due to fall in southern England in an area between the Isle of Wight and Suffolk, where an inch of rain could fall on Monday.

Gloucestershire and Worcestershire could see 10 or 15 millimetres of rainfall, forecasters said.

Environment Agency floodline: 0845 988 1188