Tension was highest in the immediate vicinity of the farm southwest of London where the outbreak was confirmed on Friday, raising the spectre of the 2001 crisis in which up to 10 million animals were slaughtered.

It is an "extremely tense, incredibly anxious time," said farmer John Cross, recalling the huge pyres of burning animal carcasses as the industry went up in smoke.

"It's only six years ago the last episode we had, the horrors of that episode are still very fresh in people's minds. Farmers are well aware of what an opportunistic aggressive virus this is," he told BBC television.

Many farmers are only just recovering from the 2001 foot and mouth epidemic, which cost the British economy an estimated eight billion pounds (16.3 billion dollars, 11.9 billion euros).

And the prospect of another devastating epidemic would only add to a string of crises that have brought British rural communities to their knees.

Many farmers are struggling to get by in the face of falling prices and increasing competition from foreign rivals, who can for example provide whole chickens for sale in British supermarkets for a mere two pounds (three euros).

The recent floods have not helped. As well as wiping out huge swathes of crops, the wettest May, June and July since records began in 1766 has put off tourists from visiting the countryside.

And Britain is still feeling the backlash from the mad cow epidemic which gripped the country in the 1990s. British beef products are still banned in the United States.

The return of foot and mouth would for many be the final straw.

"Those who managed to survive the crushing hardship of the last outbreak, exacerbated by slow and inefficient government compensation, are in no financial or psychological shape to absorb another disaster," said the Sunday Telegraph.

Sussex farmer Jane Howard told the BBC she and her colleagues were facing nervous times once again. "As far as farmers are concerned we are all sitting here hoping," she said.

"Everyone feels absolutely sick."

Sally Robinson, from Boyd's Farm, in Wiltshire, south-west England, recalled how her farm was shut down and she lost her job due to the 2001 epidemic.

She was "absolutely devastated, numb, in complete shock, just can't believe it can happen again."

Clive Aslet, the editor at large of the weekly Country Life magazine, wrote in The Observer newspaper Sunday that memories of the 2001 pyres of cattle carcasses still haunted him.

"The news that foot and mouth has reappeared in Britain after only six years will sink everyone who can remember the last outbreak into gloom," he wrote.

Tim Bonner, a spokesman for the Countryside Alliance, said Friday: "Farmers around the country will be hoping and praying this is an isolated incident.