A group acting on behalf of 100,000 farmers launched a $7 billion class-action lawsuit against the federal government Monday.

In the suit, farmers from Ontario, Quebec, Alberta and Saskatchewan are accusing the government of gross negligence in allowing mad cow disease to devastate the cattle industry.

Specifically, they're accusing the government's federal monitoring program of losing track of 80 of out 191 imported cows it was supposed to follow in case they developed signs of bovine spongiform encephalopathy (BSE).

"By the government's own admission one or more of those 80 cattle are the most likely source of BSE in Canada," Cameron Pallett, the lawyer leading the Ontario action, said in a statement.

"Where was the monitoring? Where was the government's concern for the health of Canadians? Why did the Government fail so badly in the exercise of its regulatory responsibilities?"

"The federal government has caused billions of dollars of harm so, they get to pay billions of dollars," Pallett said, appearing on Canada AM.

According to the statements of claim, Ottawa introduced a regulation in 1990 that allowed feeding cattle parts to other cattle -- which is how BSE is transmitted.

But that was two years after Great Britain had banned the practice; and three years after Canada banned cattle imports from the UK that weren't from farms certified as free of the disease.

The lawyer leading the Quebec suit calls the government "grossly negligent" in not taking into account and applying the common and scientific knowledge of how BSE is spread.

"The entire world knew about it," lawyer Gilles Gareau told The Canadian Press.

The government would not comment "until there has been an opportunity to review the full statement and assess the issues," said Elizabeth Whiting, a spokesperson for Agriculture Minister Andy Mitchell.

At least one cow imported from the UK in the late 1980s was eventually ground up into feed, infecting a number of cattle that ate the feed, according to the lawsuit.

Ridley Canada, whose parent is Australia's largest stockfeed producer, is also named in the lawsuit for allegedly producing the feed.

The farmers allege that the company knew, or should have known, that its feed could be contaminated by BSE.

Quebec farmer Donald Berneche told The Canadian Press that Ridley should have modified its feed recipe before the government ordered it to do so when it banned feed using ruminant meat and bone meal in 1997.

He alleges that the company by then had already undertaken to conform to stricter requirements in other markets.

According to the statement of claim, the company recklessly continued using the ruminants and bone meal in its Canadian products because it was cheaper than using soybeans.

The Minnesota-based Ridley is one of North America's leading animal nutrition companies. Its Canadian headquarters are in Winnipeg.

The company said in a release: "We are confident that the allegations will prove meritless and we intend to vigorously defend this suit."

A 2003 government investigation into the BSE case found no wrongdoing on Ridley's part.

With a report from The Canadian Press