Half the strains of a deadly food poisoning bug, which is common in supermarket chicken, are now resistant to the most effective antibiotics, a new report from the Food Standards Agency (FSA) has warned.

The campylobacter bacteria kills around 100 people in Britain each year and is responsible for around 280,000 cases of food poisoning annually.

Currently infections are treated with antibiotics known as fluoroquinolones, of which ciprofloaxin and nalidixic are the most common. But half of all strains found in poultry by the FSA are now resistant to both of the drugs, which means it man no longer be possible to treat some patients.

The problem has more than doubled in 10 years with just 15 per cent of strains resistant to ciprofloaxin and 22 per cent to nalidixic in 2005.

On Friday the FSA met with all major retailers to discuss the findings and come up with possible solutions to reduce the risk of consumers becoming infected.