Citizens UK describes itself as "the hub of community organising in the UK." It started as London Citizens

London Citizens

London Citizens is an alliance of community organisations in London in the United Kingdom. It is largely composed of faith groups including churches and mosques, schools, student organisations, union branches and residents' associations...

 in 1996, and came to national prominence during the United Kingdom general election, 2010 when all three leaders of the UK's three largest political parties addressed a large meeting of its members in what it billed as the "fourth debate", in reference to the three TV debates. The event was notable for Gordon Brown

Gordon Brown

James Gordon Brown is a British Labour Party politician who was the Prime Minister of the United Kingdom and Leader of the Labour Party from 2007 until 2010. He previously served as Chancellor of the Exchequer in the Labour Government from 1997 to 2007...

giving what was widely described as his best speech of the campaign.