Sugababes said it was an 'honour' to be asked to perform

Up to 50,000 people are expected to attend the summer event in the grounds of Windsor Great Park.

It is being held to celebrate the 50th anniversary of the Duke of Edinburgh's Award, and will be a first for the park outside London.

Prince Edward said: "I am sure the event will be a memorable experience."

Unsigned bands

The Live Life Loud Festival has been in the planning for almost two years.

As well as established musical acts, unestablished bands and artists are being asked to apply for the chance to perform by sending in a demo to a judging panel.

In a statement, Sugababes' Heidi, Keisha, and Amelle said: "It's quite an honour to be invited by HRH Prince Edward to perform in front of Windsor Castle.

"We can't wait to meet him and thank him ourselves as we've heard he's quite cheeky.

"All in all, we're just proud to be supporting a great charity in its 50th year... from everything we've heard the Royal Family certainly know how to party.

"We hope our fans will come and join us."

Camping area

As well as the traditional music festival, it will also feature an Adventure Village - an entertainment area dedicated to extreme and adventure sports.

Festival-goers will be able to climb a freestanding rock-face, skate on a synthetic ice-rink and try out a NASA developed gyroscope, as well as bungee trampolines and catapults.

Duke of Edinburgh Award participants will be able to camp at Windsor Great Park, while other festival-goers will have to find public camping grounds.

Sugababes and Lemar will take to the stage on Saturday 22 July, while Craig David will headline the next day.