The policy will affect the whole of the UK and will involve the slaughter of hundreds of thousands of sheep, cattle and pigs.

New plans to control sheep movements will also be announced this week. Downing Street sources said the movement of sheep hundreds of miles across the country to market was one of the reasons the disease had spread so quickly.

Cobra - the Government's national emergency management room beneath the Cabinet Office in Whitehall - has been opened for the first time since last year's fuel crisis.

Jonathan Powell, the Prime Minister's chief of staff and one of his most trusted lieutenants, is to head a crisis team, in effect overruling Nick Brown, the Agriculture Minister, who has been criticised for failing to bring the crisis under control. Brown has hinted strongly that the Ministry of Agriculture, Fisheries and Food may start vaccinating livestock against the disease in coming days to buy time to kill animals at risk.

However, he ruled out a national vaccination policy. 'There is no question of [that], but it is right just to consider if it would help our containment policies locally,' he said. Vaccination would mean an end to British meat and livestock exports, worth an annual £570 million, for anything from three months to two years.

The news that Maff ignored advice that would have prevented the outbreak in the first place will further embarrass the Ministry. Maff documents reveal that Seac 'felt that recycling pig waste as feed for the same species could create the potential to spread disease and recommended that the Government should remove this risk'.

The documents show that the Government agreed to 'consult on the issue of [a ban on] feeding catering waste containing pig material to pigs' - exactly what is believed to have happened at Heddon-on-the-Wall, Northumberland, where the outbreak started. No ban was imposed.

'Pigswill is only one of a number of possible causes being considered. The Government takes a range of scientific advice in policy decisions,' a Maff spokesman said. The logistics of the cull are continuing to cause problems, with the Army helping vets.

'It's like a war,' said one vet yesterday. 'There's mud up to your knees and carcasses everywhere.'