The 24-hour Big Tweet For Missing Children campaign gets underway with support from The Sun, Stephen Fry and Outdoor Media Centre

The Sun is supporting the campaign by retweeting the charity’s appeals to its 900,000 twitter followers and has also pledged to donate £10,000 to Missing People if 50,000 retweets are reached.

Dominic Mohan, editor of The Sun commented: “We are delighted to be able to use the great reach of The Sun and its loyal followers to support this unique appeal and be part of the opportunity to bring good news to the many thousands of family members and friends desperate to hear that loved ones are safe and well.”

Last year three children were found after the Big Tweet.

Stephen Fry, a patron of Missing People also pledged his support. He said: “A staggering 140,000 children go missing in the UK every year. On International Missing Children’s Day I will join the charity Missing People in harnessing the power of social media to help find missing children.”

Meanwhile the Outdoor Media Centre has supported the charity with a digital outdoor campaign, streaming Missing People's tweets direct to a network of digital billboards across the UK over the 24 hour period using OpenLoop.

It is hoped the outdoor campaign, which covers London, Birmingham, Manchester and Glasgow and is supported by JCDecaux, CBS Outdoor, Primesight, Ocean Outdoor, blowUP media, and Outdoor Plus, will extend the reach of Missing People's twitter feed and help raise awareness and participation amongst the out of home audience.

Bill Wilson, operations director at the Outdoor Media Centre said: “We are delighted to be on board with The Big Tweet for Missing Children. Digital Out of Home media now has the technology and infrastructure to deliver timely and responsive campaigns nationwide. The Outdoor Media Centre and our members feel strongly about this cause and are committed to helping to extend the search for Missing Children.”