Union J will headline the final day of Barclaycard presents British Summer Time Hyde Park.

The former 'X Factor' contestants will be topping the bill on the Family Day of the music festival on Sunday 28 June, and will be joined by 'Britain's Got Talent' winners Collabro, as well as Dick & Dom, Sam & Mark and Justin Fletcher.

Dick & Dom said: ''We're really looking forward to being your twisted ringmasters of the main stage for this massive family event. We'll be bringing you the biggest names and best acts. It's going to be THE best day out for the kids.......and you!!''

Sam & Mark found fame together on 'Pop Idol' and the BAFTA award-winning children's presenters will be bringing their 'On the Road Show' to the London festival.

The duo said, ''We're so excited to be bringing our 'On The Road Show' to Hyde Park. It's a show that we hope will entertain the whole family; from kids, older brothers and sisters, Mums, Dads, Grandmas and Granddads! It will be jam packed with lots of fun, games and laughs. It's going to be awesome!''

Other acts on the day will be 'Horrible Histories', 'Brainiac Live!' and theatre company 'Chickenshed'.