Government inspectors found 53 per cent of fresh chicken sold in Scotland were positive for a strain of E.coli resistant to antibiotics.
The bug can make you seriously ill, and in certain instances can be fatal.
The new research, carried out by the Department for Environmental Food and Rural Affairs and Public Health England, tested chicken samples from supermakets, convenience stories and butchers.
Campaigners say the emergence of these so-called superbugs is due to the use of antibiotics on livestock in the UK over decades.
Colin Nunan, scientific advisor for the Alliance to Save our Antibiotics, said: “For years, the poultry industry was systematically injecting day-old chickens in breeding flocks with modern cephalosporins, despite these drugs being classified as critically important antibiotics in human medicine.
“This practice was in breech of an EU directive, but although we alerted the Government in 2006, the official watchdog, the Veterinary Medicines Directorate, refused to take any action.
“Unfortunately we are still seeing the effects of the VMD’s inaction.”
The Government and food industry say consumers will be safe if they handle chicken carefully and cook it properly.
Dr Mark Holmes, reader in microbial genomics and veterinary science at Cambridge University, said: “People do get food poisoning and everytime someone falls ill, instead of just getting a food poisoning bug, they might also be getting a bug that is antibiotic resistant.
“If they end up developing sepsis or a urinary tract infection, they may well find they have a bug that is resistant to the first choice antibiotic, the bug could be out of control, it can even lead to death.”
UK Rural Affairs and Biosecurity minister, Lord Gardner, said: “Antibiotics resistance is the biggest threat to modern medicine and we must act now to help keep antibiotics effective for future generations. This report shows the hard wok of our vets and farmers is already making a real impact.”