Caroline Allen, vet and Green Party Spokesperson on Animal Issues said: "It is increasingly clear that the overuse of antibiotics is putting the effectiveness of these vital drugs at grave risk.

"The use of antibiotics to prop up a farming system where animals are kept in inhumane and completely unsuitable conditions, suffering great stress, is surely one of the great scandals of our time.

"Are we really willing to risk our ability to perform chemotherapy, routine surgical procedures and treat infections so we can eat a cheap burger?’

The Chief Medical Officer, Professor Dame Sally Davies has warned that a post-antibiotic era is approaching, in which common infections will again kill, and routine operations such as hip replacements will become too risky to carry out.

Cancer treatment will no longer be possible. The World Health Organisation has called it a major global threat to public health.

There are now a significant number of studies that show how resistant bacteria are spreading from factory farms in to the human population.