Their threat, which includes a plan to block Dover with tractors, came yesterday despite an EU legal threat and a plea from the Prime Minister, Tony Blair.
Protesters in Wales have vowed to maintain round-the-clock pickets in a bid to force the Government to take action over their plight.
Meanwhile, Welsh farmers' wives added their own protest by setting up a stall outside a Tesco supermarket at Cardigan and giving away bags of free vegetables to highlight the gap between shop prices and the earnings of farming families.
The Prime Minister said he understood the concerns of the protesters but warned that they must stay within the law.
It also emerged this weekend that British families continued to eat beef on the bone from BSE-affected herds for years after the rest of Europe had stopped.
The bones were taken out of British beef exported to EU countries, but left in for consumption at home, even though scientists were advising the government that removing them was the best way of insuring against the spread of the disease to people.
This startling evidence that Britons were for so long treated as second- class consumers is bound to be examined by the inquiry into the BSE crisis to be set up over the next two weeks. It was only on Wednesday that ministers banned beef on the bone in Britain, after the official Spongiform Encephalopathy Advisory Committee warned it might pass on the disease.
Yet Germany banned all beef on the bone from Britain on health grounds at the beginning of this decade.
After a crisis in confidence in British beef on the continent in June 1990, a variation of this ban - covering beef from herds that had had cases of BSE - was extended throughout the European Union. Switzerland, which is not part of the EU, promptly banned all British beef because it feared being sent meat the rest of Europe would not accept.
The ban continued on the continent until March 1996 when all imports of British beef were stopped following the disclosure that it was likely to have given people CJD. The result, say food experts, was that British dinner tables became "dumping grounds" for dubious beef.
In 1990, the then shadow agriculture minister, Dr David Clark, raised the double standards with the agriculture minister, John Gummer, in the House of Commons, only to be told that he was making "wild statements" and misleading the public.
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