A number of companies have vigorously opposed stricter regulations arguing that, without antibiotics, not only will animal welfare be compromised but also that food prices will increase. Until 2017 antibiotics were widely used as growth promoters on US farms, helping livestock grow fatter more quickly. When farm animals are sick it is sometimes necessary to give them antibiotics. But US farmers are still allowed to routinely give them to healthy animals to control disease, a practice many believe can often take place as a way of dealing with overcrowding and poor hygiene.

Dr James Rogers, director of Food Safety Research & Testing at Consumer Reports and a former FSIS employee, said: “There is intense pushback because we are talking about an economic effect, that if they were not allowed to use antibiotics, especially for growth promotion, you’re going to get fewer pounds per chicken, which means less money.”

In November the US Department of Agriculture rejected further restrictions recommended by the World Health Organisation (WHO). The guidelines proposed a ban on giving healthy animals antibiotics important for human medicine. The USDA acting chief scientist, Dr Chavonda Jacobs-Young said they were “not in alignment with US policy and not supported by sound science”. Hoefner, who is a regular attendee at the monthly meetings between industry representatives and USDA officials, described her comment as “outrageous”, given the weight of knowledge behind the WHO guidelines.

Last year agribusiness organisations, including all livestock, crop and tobacco industries, spent more than $131m on lobbying in the US, according to the Center for Responsive Politics. Critics say industry is perceived to have been able to tighten its grip on the USDA during the Trump administration, especially on the issue of antibiotic use. Hoefner said: “We were making some inroads in the last administration here in the US, but even then it was difficult. We weren’t making huge strides but we were making some strides. But now it’s totally impossible so we’ll just have to wait this out.”

But Prof Laxminarayan is more hopeful. Referring to Elanco’s ENOUGH Movement, he said: “I see all of this as the last cries before it goes down,” adding: “it will still have a role in animal health, but the days of pushing antibiotics in livestock for growth promotion, their widespread use on farms to prevent disease, are soon to be over.”