text: Mayor of London Boris Johnson samples Gin during a visit to Sipsmith's Gin distillery in Chiswick, London, the first copper distillery in the capital for 200 years. PRESS ASSOCIATION Photo. Picture date: Friday April 17, 2015. Mr Johnson has not ruled out becoming a minister in the first year of a Tory government but said David Cameron would not be in favour of such a move. Mr Johnson insisted he could not see how a ministerial position would be compatible with his job as Mayor of London, which will end in May 2016. After that the road would be clear for Mr Johnson to be promoted to government if the Tories form it and he becomes MP for Uxbridge and South Ruislip. But Mr Johnson stressed that his current mayoral position was like running a big budget government department already. See PA story ELECTION Boris. Photo credit should read: Anthony Devlin/PA Wire