Boris Johnson to end speculation about his Brexit position in 25 minutes.
London's mayor will make a statement outside his Islington home at 5pm, writes Simon Harris.
Boris Johnson has said that he will join the campaign for Britain to leave the European Union to get a 'better deal' for the country.
The front-runners to replace Boris Johnson as London mayor were today pitched into a new battle on opposite sides in the debate over Europe.
Boris Johnson's in/out dithering over Europe can be traced back to a forgotten report commissioned by London's mayor almost two years ago.