At London Zoo this week, Dragons' Den star Peter Jones and founder of Wikipedia Jimmy Wales helped launch the second Global Impact Challenge - a competition run by Google which tasks UK charities with coming up with innovative ways of leveraging technology to help tackle "the world's toughest problems and transform lives."

The competition is open to all UK charities and they have until 6 June to submit proposals, with a list of finalists being announced on 21 July before the winners are announced on 31 July.

Three winners will be chosen by a panel of judges with a fourth being chosen by a public vote. All four will receive funding of £500,000 as well as mentoring from Google. There will be a further six runner-up prizes of £200,000.

The judges panel this year includes Jones and Wales, as well as broadcaster and director of Red Nose Day Emma Freud, Nesta's Innovation Lab executive director Helen Goulden and Google's Matt Brittin and Jacquelline Fuller.