Sir Brian May has resigned as the RSPCA’s vice president over what he called “appalling” animal welfare standards in farms certified under its scheme.The certified RSPCA Assured label, which indicates that meat, fish, eggs and dairy products have been produced to strict standards which exceed the UK’s legal requirements, is being reviewed by the animal welfare organisation.Almost 4,000 farms participate in the scheme, which means they can use the label to inform supermarket shoppers of their superior animal welfare standards.Queen guitarist Sir Brian, who has long campaigned on animal welfare rights, and is a co-founder of the Save Me Trust, which campaigns for the rights of foxes and badgers, shared his letter of resignation on Instagram.The letter read: “It is with profound sadness and not without massive soul-searching that today I have to offer my resignation as a vice-president of the RSPCA."