Pigswill facts

Mostly catering or food waste Farmers using swill must be licensed Swill heated at 100°C for one hour to kill bacteria Used by about one per cent of pig farmers About 80,000 swill-fed pigs

Prime Minister Tony Blair has also hinted that the government could change policy and start vaccinating against the disease.

The number of cases around the UK has now reached 667, with 33 new outbreaks confirmed on Tuesday.

Northern Ireland has been given the go-ahead to resume livestock exports to Europe after being granted regional status by the European Commission's Standing Veterinary Committee in Brussels, according to sources at Stormont.

However the European Union is expected to extend a ban on French exports of livestock, and has authorised the Netherlands to begin a "firewall" vaccination around infected areas.

Five outbreaks of the disease have been confirmed there, while two cases have been found in France and one in the Republic of Ireland.

Click here to see 1967 foot-and-mouth figures compared to 2001 figures.

In the UK, the Army has already started a mass burial of sheep in Cumbria to help clear the huge backlog of slaughtered animals awaiting disposal.

Up to half a million sheep will be buried

The slaughter of a further 40,000 animals on Anglesey is due to begin on Tuesday in an attempt to halt the spread of the disease there.

Officials are still investigating the Northumberland pig farm, suspected to be the point from where the virus spread across the country.

The Times newspaper reported that a container of illegal meat, clearly labelled for a Chinese restaurant, was found hidden inside a load of household goods after confirmation of the case in Heddon-on-the-Wall.

Mr Brown was likely to say in his Commons statement on Tuesday afternoon that infected meat imported into the country was a possible cause of the disease, said the prime minister's spokesman.

Crisis in the UK

Total confirmed cases 667 663,00 animals due for slaughter 419,000 already slaughtered 315,000 carcasses destroyed

He is also expected to outline two Maff consultation documents, one floating the idea that other animals might be subjected to the 21-day prohibition on resale to which pigs are already subject.

The other would deal with whether, given the outbreak, it was still appropriate for pigswill to be used as a form of feed.

But the farmer at the centre of crisis said the government was creating a "smokescreen" by suggesting swill could be behind the current crisis.

Bobby Waugh, who runs the Heddon-on-the Wall farm in Northumberland, said: "I have been treating swill and feeding pigs for more than 25 years since new regulations were introduced in 1974 and have never had a problem.

"I honestly don't think I am at the heart of this."

Situation changing quickly

Only 1% of pigs in Britain are fed swill and a ban would affect fewer than 100 farmers.

An official report into the outbreak is also expected to reveal that the disease had been present in the UK for at least three weeks before it was spotted.

Earlier, the prime minister said there had been a significant shift in opinion about vaccination to combat the disease.

In an exclusive interview with BBC Radio 4's Farming Today he said: "As you track the disease and see how it spreads, things that may have seemed utterly unpalatable a short time ago, have to be on the agenda," he said.

Until now, the government has favoured a slaughter and burn policy, avoiding vaccination out of concerns that it would hit future export markets as the UK would lose its status as a "disease free" zone.

'Every resource of government is being put to deal with it'

Supporters of vaccination argue that it could be used to "ring fence" outbreaks.

Mr Blair said opinions were rapidly changing: "A few days ago even, this was generally regarded as anathema to very large parts of the farming community."

He acknowledged vaccination would have consequences for the farming industry for the future.

"But we keep this under review, we are urgently looking at all those possible options for the future," he said.

Mr Blair dismissed suggestions the crisis in the countryside was not a priority for the government.

"Every single sinew, every resource of government is being put to deal with it," he said.