Agriculture Minister Nick Brown admitted that the first outbreak of the disease on a pig farm in Northumberland did start three weeks earlier than at first claimed, as we suggested in our update yesterday - a potentially disastrous delay which allowed the disease to spread throughout the UK.

He explained that this particularly strain of the disease only showed very minor symptoms in sheep and had gone un-noticed whilst hundreds of animals were being transported to markets all over the country.

After the minister's statement, which also suggested the first outbreak was caused by illegally imported meat, the normally equable NFU President Ben Gill, who farms at Easingwold, near York, came close to blowing his top.

Farmers "would be fuming with rage," he said, and added: "It is quite unbelievable that a consignment of meat which should never have got into this country could have could have paralysed British farming in this way in just a matter of weeks."

Mr Gill also expressed grave doubts about the introduction of a vaccination policy but added that it might be acceptable as a "last resort" so long as it did not replace the slaughter policy.

• Another development of grave concern to North Yorkshire farmers and rural businesses was the confirmation of a new outbreak near Northallerton, many miles from the existing clusters near Hawes in Wensleydale and Queensbury in West Yorkshire.

And in the House of Commons, Skipton and Ripon MP David Curry commented: "If this disease gets onto the Pennine uplands, it will spread south like a brush fire."