The Tory former minister told the inquiry into BSE that it was the worst crisis he had ever dealt with.

The worst crisis of my career - William Waldegrave

He strongly denied the Conservative government underplayed the risks of 'mad cow disease' to human health to protect the farming industry.

Giving evidence to the inquiry in London, Mr Waldegrave said that public health was always the paramount concern of both the agriculture and health departments while he was in charge.

While he was health secretary in 1990-92 and agriculture minister in 1994-95, ministers were confident that the best scientific advice was that there was no link between BSE and the human disease CJD, said Mr Waldegrave.

Waldegrave said he thought BSE was diminishing

So when the later health secretary Stephen Dorrell announced in 1996 that there was indeed a link, the news came as a thunderbolt, he said.

"This was the biggest emergency of my political career, the most difficult and important crisis which I have ever dealt with.

"All through my period at the Ministry of Agriculture, it felt the opposite. It felt like the epidemic was disappearing slowly from animals."

Tough on public health

Mr Waldegrave said that while he was agriculture minister, food safety always took priority for him over the interests of the farming industry, but said it was wrong to see the two as mutually opposed.

Waldegrave said he tried to keep anything potentially infected out of the food chain

He said: "If there was the slightest question - as the world has now seen - over the safety of British food, it was a catastrophe for the industry.

"It seemed to me that by far the best way of protecting the industry was to be tough on public health issues as well."

Mr Waldegrave said he always encouraged his advisers to look into "dissident" theories.

The best advice was that there was only a remote possibility of danger to humans, but that it was nonetheless best to keep potentially infected agents out of the human food chain, he said.

He added: "This policy was often criticised at the time but seems to me to have been wise."