Thames barrier fears

Emergency planners believe terrorists could attack the Thames Barrier - potentially flooding central London and causing ?30 billion worth of damage.

Among the areas that would be affected are the Palace of Westminster, 10 Downing Street and several square miles of the most expensive homes and office space in the country.

Plans to cope with the aftermath of an attack have been incorporated into a security review by senior MPs and officials at the House of Commons. A major breach could mean several feet of water surging through streets and sluicing sewage out of drains in scenes like those portrayed in the disaster movie The Day After Tomorrow.

The last time central London flooded was in 1928, when 14 people drowned. Severe flooding in 1953 caused 300 deaths around the Thames estuary and the east coast.

"If this flood had reached central London's highly populated low-lying areas the result would have been horrifying," said a spokesman for the Environment Agency, which operates the barrier at Woolwich. He added: "Security is constantly reviewed for all sorts of reasons."

Disaster planning is carried out by the London Resilience committee headed by government minister Nick Raynsford. His office said the capital was "as prepared as it can be" for any eventuality.