An international food labelling scheme is to allow five times more lice at salmon farms, prompting Scotland’s official fisheries management body to withdraw its support.

The Aquaculture Stewardship Council (ASC), whose logo on supermarket packaging certifies approved brands of farmed fish as “environmentally and socially responsible”, is increasing the number of lice permitted on caged salmon in Scotland from 1 February.

The change has been condemned by Fisheries Management Scotland (FMS), which brings together 66 angling and river groups. The new standard “fundamentally undermines the integrity of the ASC scheme” and means it is no longer a “credible” way of protecting wild fish, FMS said.