Prime Minister David Cameron has said he is "devastated" to hear of the death of his constituency chairman at Glastonbury Festival.
Christopher Shale, chairman of West Oxfordshire Conservative Association, was found in a portable toilet in a backstage VIP area.
In a statement, Mr Cameron said Mr Shale was a "close and valued friend" and a "big rock" in his life.
Mr Shale, a father who was in his 50s, was believed to have been staying in a Winnebago at the festival. Police are investigating the cause of death.
Mr Cameron, the MP for Witney, said he and wife Samantha were great friends of Mr Shale's, a successful businessman.
"Sam and I were devastated to hear the news about Christopher," the Prime Minister said. "He was a great friend and has been a huge support over the last decade in west Oxfordshire. A big rock in my life has suddenly been rolled away.
"Our love and prayers are with Nikki and the family. They've lost an amazing dad, west Oxfordshire has lost a big and wonderful man and like so many others Sam and I have lost a close and valued friend."
Glastonbury Festival supremo Michael Eavis described the death as "a suicide situation", although police said it was still too early to say. Other sources suggested it was a heart attack.
Mr Shale, who was quoted in a Mail on Sunday article on the difficulties his party faces in recruiting new members, was discovered by officers shortly after 9am on Sunday.
A distraught woman, staying in the backstage area between the Pyramid and other stages, was seen being comforted by officers. Police confirmed several of the dead man's relatives were at the site.