Charities could miss out on up to £1m because of poor ticket sales at this year's Glastonbury Festival.
Past downpours and controversy over the decision to invite rapper Jay-Z to headline the event have been blamed for the Somerset event not selling out in advance this year.
With 3,000 full tickets at £155 each unsold the day before the event opened on Wednesday, organisers were offering extra £50 Sunday-only tickets.
Michael Eavis, organiser of the event, said rising costs such as fuel for tractors and generators would also eat into charity profits.
Non-profit organisations including Greenpeace, Oxfam and WaterAid as well as scores of smaller causes had hoped to receive a £2m slice of the profits from the event.
Eavis told the BBC: "The charity money will have to be reduced, I think. We've got £1m going to charity already, but it's the second million that's the problem if we don't sell out."
