David Cameron: 'Collective power is amplified by membership of EU'
Prime Minister David Cameron and US President Obama have stressed their support for the UK to stay in the EU at a news conference in London.
Mr Obama is in the country for a three-day visit with his wife Michelle.
During a press conference Cameron spoke about the "special relationship" with the US, and said: "Our collective power and reach is amplified by Britain's membership of the European Union".