The chicken industry is facing calls to halt the expansion of intensive production in the River Severn catchment, with campaigners warning that the river is at risk from the same pollution that has blighted the River Wye.

An outcry over the ecological plight of the Wye has effectively halted the proliferation of intensive poultry units across the catchment. Campaigners say that the pollution threat is being transported “from one catchment to the other”.

The ecological health status of the Wye was downgraded in May last year by Natural England. Campaigners warn of phosphates from poultry litter that are being washed into the Wye and fuelling the growth of algae blooms, which can suffocate a river.