They call for a halt to chicken imports and a focus on domestic breeders instead.

European Union rules allows for free-range laying hens to be kept inside for up to 16 weeks in the event of a bird flu outbreak and their eggs can still be labelled free range.

China has reported 21 human infections with the H5N6 subtype of avian influenza in 2021 to the World Health Organization, compared with only five last year.