The company had considered a new sourcing protocol in which animals could be treated by antibiotics providing it was ‘necessary for their continued health’.

However, Steve Ells, Chipotle chairman said that after ten years of an antibiotic and hormone free sourcing policy, this commitment was not about to change.

This does not mean that the issue is closed. Chipotle will continue to evaluate the issue of necessary treatment of cattle, pigs and poultry with antibiotic medicine.

Mr Ells said: “We are always looking to improve our protocols in order to ensure that we are buying the very best sustainably raised ingredients.

“Many experts, including some of our ranchers, believe that animals should be allowed to be treated if they are ill and remain in the herd. We are certainly willing to consider this change, but we are continuing to evaluate what’s best for our customers, our suppliers and the animals.”