Announcement comes a day after the referendum announcement<br /> Informed former classmate David Cameron by text message<br /> Boris Johnson has announced he plans to lead the campaign for Britain to leave the EU.<br /><br /> Speaking to reporters on the doorstep of his home in the UK capital, the flamboyant mayor of London says the decision involved a ‘huge amount of heartache.’<br /> <br /><br /> .MayorofLondon</a> Boris Johnson announces he backs campaign for UK to leave EU https://t.co/Kc0g3oBq46</a> #EUref</a> pic.twitter.com/poUWpWwBs5</a></p>— BBC News (UK) (BBCNews) February 21, 2016<br /> NEW: Big boost for Leave campaign as Boris Johnson announces he will campaign for Brexit. https://t.co/NjRl3bx6zJ pic.twitter.com/Z40Ro5lm4m— PoliticsHome (@politicshome) February 21, 2016<br /> <br /><br /> Brexit: Why has Boris Johnson backed the Out campaign? https://t.co/MyEHO851m2 pic.twitter.com/qXwyBjTtzh— Financial Times (@FT) February 21, 2016<br /> Boris is an ‘Out-er’<br /><br /> Insiders say Johnson’s decision is a huge boost to the “Out” campaign.<br /><br /> He described the EU as “eroding British sovereignty”:<br /><br /> “There should be no confusion between the wonders of Europe and holidays in Europe and fantastic food and friendship and whatever else you get from Europe and the political project.”<br /><br /> “But I would like to see a new relationship based more on trade and cooperation and less, as I said, of this supranational element.”<br /><br /> It is also a knock for David Cameron. The UK Prime Minister has been trying to build a consensus to back the campaign to stay “In”.<br /><br /> Cameron is on record as saying the UK will be “safer and stronger” within the EU.<br /> <br /><br /> Who is Boris Johnson?<br /><br /> <br /><br /> Alexander Boris de Pfeffel Johnson<br /> Born 1964 in New York<br /> Lived in Brussels suburb of Uccle for 2 years as a child<br /> Classmates with David Cameron at prestigious Eton School<br /> Former journalist<br /> Elected Mayor of London 2008<br /> MP for Uxbridge and South Ruislip<br /> Father is a former centre-right MEP and employee of the European Commission<br /> (Source: Wikipedia https://en.wikipedia.org/wiki/Boris_Johnson)<br /> <br /><br /> Why Boris Johnson?<br /><br /> <br /><br /> Boris, or BoJo as his name is sometimes shortened to, has arguably the highest Conservative profile after David Cameron.<br /><br /> With his shock of blond hair and eccentric manner, insiders say he is sure to not go unnoticed by referendum voters.<br /> <br /><br /> In pictures<br /><br /> <br /><br /> BREAKING: London Mayor Boris Johnson confirms he’ll campaign for Britain to quit EU https://t.co/YUkJFEWBQt pic.twitter.com/X5huRtMNhm— Bloomberg Business (@business) February 21, 2016<br /> <br /><br /> Boris Johnson’s skewed priorities are creating a public health disaster https://t.co/cck4snh1EK via leftfootfwd</a> pic.twitter.com/cVveuGYZbY</a></p>— Michael Vine (mpvine) February 10, 2016<br /> You said Bear Grylls – I was thinking more Boris Johnson #FriendsWithTi