The results of the second quarter of the survey, which were published on 25 February, showed 11 per cent of chickens tested positive for the highest level of contamination, down from 19 per cent in October to December 2014.

However, the FSA said that Campylobacter levels were still too high and the bug remains a top priority, and said it is setting itself a new target to reduce the number of human cases of Campylobacter poisoning by 100,000 a year.

The FSA's method for testing Campylobacter levels has been to measure the amount of the bug on the neck skin of the chicken – this is because this is generally the most contaminated part of the bird.

But the agency said that many processors are now removing the neck skin before birds reach retailers.

Although the FSA said this measure reduces Campylobacter and helps protect consumers, the different amounts of neck skin on each carcass now make it impossible to fairly compare contamination between retailers using this method.

A restart of testing in summer using a new method is the next goal, and in the future retailers may be asked to provide their own sampling results to an FSA standard.

Steve Wearne, Director of Policy at the FSA said: "Tackling Campylobacter remains our number one priority. The ultimate test to show whether our campaign is working is to see whether fewer people get ill.

"That’s why we want to see 100,000 fewer cases of Campylobacter each year from the end of March 2017. So there’s no let up for industry: we want to see continuing efforts to reduce this bug on our chickens."