Google is giving away £2m to non-profit organisations to develop technologies with the potential to "change the world".
As part of the its Global Impact Challenge competition, UK charities will be invited to pitch their ideas to a panel of judges including Sir Tim Berners-Lee, the inventor of the world wide web, Sir Richard Branson and Google's European boss Matt Brittin.
Four successful charities will each be awarded £500,000, and will also receive 10 Samsung Chromebooks as well as support from Google's employees.
Berners-Lee said in a statement: "The web's contribution to economic progress has been much celebrated, but I believe that we are only scratching the surface of its potential to solve social and political problems."
Last year's Global Impact Challenge finalists included organisations looking to use technology to address everything from water scarcity to endangered wildlife.
The first round of awards went to projects including helping under-privileged students to access maths and science education, and deploying water quality monitoring sensors.
While the last Challenge was open to charities from around the world, the competition announced today is only open to those in the UK.
The 10 finalists will chosen by a team of Google employees, and announced on 17 May.
On 3 June the 10 finalists will pitch their ideas at Google's UK headquarters in Victoria, London to the judging panel, which also includes communications expert Jilly Forster and Google's director of giving Jacqueline Fuller. Three winners will be chosen by the panel of judges, while the final winner will be selected by a public vote.