Charity ShareAction, which is working towards responsible investment practices worldwide, called on consumers to email McDonald’s CEO Steve Easterbrook about antibiotics using their online form.

The problem of resistance by pathogens to antimicrobial drugs is currently causing grave concern, and ShareAction blamed resistance development on overuse of these medicines in animal agriculture.

The charity said that whilst some progress has been made in McDonald's US poultry supply chain, "investors are increasingly worried about double standards between beef, pork and poultry".

McDonald's USA recently completed a pledge to stop using antibiotics important to human medicine in its poultry supply chain seven months early.

In its suggested email to the McDonald's CEO, ShareAction singled out preventative use of antibiotics as a key concern, suggesting that McDonald's should set timelines to phase out the use of medically important antibiotics for this purpose across its entire meat and dairy global supply chain.

McDonald's policy on antibiotic stewardship states: "We recognise the importance of continuing to evolve our position on antimicrobial use."