Gnarls Barkley, who famously became the first band to hit the UK number one through downloads alone with 'Crazy', cite problems with Cee-Lo's vocal chords as the reason for cancelling their appearance in Laois, as well as other four European dates.
The organisers state: "The promoters of Electric Picnic are hugely disappointed and are working to find a replacement but due to touring schedules and the short time scale it is proving difficult."