Supermarkets should make a joint stand and show consumers they are serious about Campylobacter by taking a “more visible and co-ordinated industry wide approach” against the problem.

Which? has written to the UK’s seven major supermarkets to demand they take more action to tackle campylobacter, a bacteria which can be found in chickens and lead to serious illness.

The group has called on Asda, Co-op, Marks & Spencer, Morrisons, Sainsbury’s, Tesco and Waitrose to make publicly available plans for how they will tackle Campylobacter, along with clear timeframes for when this will happen.

In its letter to the supermarkets, sent today, Which? says that almost six weeks have passed since the Food Standards Agency (FSA) released data showing “scandalously high levels” of the bacteria in chicken, and that “consumers need reassurance that supermarkets are taking this seriously and doing all they can to address the problem”.

Some 30,000 people have signed a Which? campaign to make chicken safe, and the organization said 60% of consumers were concerned about high levels of campylobacter in supermarket chickens, with 75% saying they thought they were too high.

Half of consumers were unhappy about the amount of information about campylobacter levels in chicken.

“We have previously been in touch with your teams and are calling for every major supermarket to publish a plan of action by the end of January and to make this publicly available and published on your website, with a timeframe for taking action.”

The plan should include both immediate and planned interventions along the food chain, Which? said, such as incentivizing farmers to improve controls to the use of blast surface chilling, to reduce levels of campylobacter as quickly as is feasible.

Andrew Opie, director of food and sustainability at the British Retail Consortium, said food safety was retailers’ “top priority” and that initiatives such as leak-proof and oven ready packaging, safe handling information on labels, websites and in in-store magazines had been introduced to help people understand the risks and minimize contamination.

Set goals and publish the data.