The Guardian reports that Christopher Shale, British Prime Minister David Cameron's constituency aide and leader of Oxfordshire-based Conservative group West Oxfordshire Conservative Association, was found dead at this weekend's Glastonbury Festival.Shale's body was found in a portable toilet around 8:45 a.m. BST Sunday morning in the festival's backstage area. Sources tell The Guardian that Shale most likely suffered from a heart attack, although the cause of death has not officially been announced yet, as The Guardian later reported.