The action is being led by Lynda Davies of the Association of Swill Users, on behalf of the 62 farmers who were forced out of business without compensation when the government banned swill feeding.
The claim centres on a government vet, who the group alleges was negligent, after a farm in Northumberland had its swill feeding license renewed, despite evidence it did not meet the strict hygiene standards practised on other swill feeding farms, they claimed. Ten days later FMD developed at the farm.
The group have decided to go to court now because of repeated delays in the publication of an inquiry by the parliamentary ombudsman, which after six years, they hoped would clear their names.
Davies told Farmers' Weekly: "We have been waiting in good faith for the ombudsman's report into government maladministration over foot and mouth. But we have been told it has been delayed again. We now have no choice but to go to court."
Defra declined to comment for legal reasons.