LONDON - Britain imposed a nationwide ban on the movement of livestock Friday after officials confirmed an outbreak of the highly infectious foot and mouth disease on a farm near London.

Prime Minister Gordon Brown cut short a vacation elsewhere in the country and was due back in London on Saturday to deal with the crisis.

"Our top priority is to prevent the spread of this disease in order to protect farmers' stock," his spokeswoman said.

The emergency recalled the last foot and mouth epidemic, in 2001, when between 6.5 and 10 million animals were destroyed, the tourism industry gutted, the army called in, and a general election postponed.

The latest outbreak of the disease -- which passes very easily among ruminants but is only very rarely contracted by humans -- was detected on a farm near Guildford, southwest of London.

All cattle on the farm were to be culled.

A spokesman at the Department for Environment, Food and Rural Affairs (Defra), said the country's chief veterinarian "has confirmed foot and mouth disease" following laboratory tests.

The situation prompted a hastily convened meeting of COBRA, Britain's emergency contingencies cabinet, which Brown, on holiday in Dorset, southwest England, took part in by telephone.

His spokeswoman said Brown would return to London to chair another COBRA meeting.

She said measures being put in place "are tested and well-established."

A three-kilometre protection zone and a 10-kilometre surveillance zone have been placed around the affected farm.

"Nationally no animal movements are allowed except under licence," a Defra spokesman said.

"Controls are in place on movement of animal carcasses, animal gatherings, shearing and dipping are restricted, and all farms must increase levels of biosecurity.

"In both the protection and surveillance zones, there will be requirements for increased levels of biosecurity on farms, movement controls, controls on transportation of dung/manure and treatment of animal products to ensure destruction of the foot and mouth disease virus."

Britain's environment secretary, Hilary Benn, was due to return to London from his holiday in Italy.

The European Commission has also been informed.

The 2001 outbreak dealt a blow to Britain's economy, costing it an estimated eight billion pounds (16.3 billion dollars, 11.9 billion euros).

Then, 2,000 cases of the disease were detected on farms throughout the country. To prevent the spread of the disease, public rights of way across land were closed, causing huge losses in revenue for the tourism industry as well as for agriculture.

- AFP /ls