Gordon Brown said: “We have restricted the disease to a limited area of this country. The risk of it spreading out of these areas is low if not negligible.”

Fears of a wider outbreak were aroused by the reporting on Thursday of a possible first case of the disease outside the 10km surveillance zone set up around the first confirmed case, on a farm near Guildford.

No animals from the herd, on a farm near Dorking, have been culled. The results of the tests on the livestock were not known on Friday, but Debby Reynolds, the chief veterinary officer, said: “The level of suspicion is low.”

A 3km-radius temporary controlled zone, in which the movement of animals is banned, has been thrown up around the farm in question. But in the rest of the country, outside the surveillance zone around the first outbreak, farmers were allowed to send their cattle to licensed slaughterhouses or have dead animals collected, though they were still banned from moving their animals for other reasons.

Source: Financial Times