When Kate Middleton marries her Prince on 29 April, an estimated two billion people are expected to tune in. Even at a time of dramatic world news, the marriage of Prince William will be the global event of the year.

Filmed throughout the weekend of the wedding, The Unofficial Royal Wedding will show the many different ways this event is being marked and what it means to the nation.

Through user-generated videos, the film will feature the instant reactions of spectators across Britain and the world as they have their first glimpse of the dress, the vows and the kiss on the balcony.

Viewers will be providing video material of their own celebrations and cameras are being provided internationally to capture reactions across the world, from a children's home in Calcutta to a party under the Brooklyn Bridge.

The programme will follow a cast of characters across Britain over the weekend with very different views on the wedding, from an anarchic ceramicist and artist who has been producing anti-royal wedding memorabilia to an ardent royalist and avid collector of royal memorabilia.

The Unofficial Royal Wedding will also feature entertaining footage from Alison Jackson's fake royal wedding. Renowned for her satirical use of lookalikes to produce paparazzi-style images, she staged royal scenes earlier this month on The Mall, followed by a reception for her Wills and Kate in a KFC and a London pub.