Union J is the first act to be announced for the undercover music festival which will celebrate its 5th Birthday on Saturday 24th and Sunday 25th May 2014.

Union-J were brought together by the X-Factor. Jaymi Hensley, Josh Cuthbert, and JJ Hamblett were Triple J before the show made the decision to add George Shelley, giving us Union J.

750 early buy tickets went on sale at 9am which are available to purchase online at www.osfest.co.uk.

Festival organisers say they have more big announcements throughout December.