PoliticsWhy Boris Johnson Is Having Another Go at Disputed Brexit PledgeFacebookXLinkedInEmailLinkGiftBoris Johnson Challenges Theresa May in Brexit Essay FacebookXLinkedInEmailLinkGiftGift this articleContact us:Provide news feedback or report an errorConfidential tip?Send a tip to our reportersSite feedback:Take our SurveyNew WindowFacebookXLinkedInEmailLinkGiftBy Robert HuttonSeptember 18, 2017 at 7:35 AM UTCBookmarkSaveLock This article is for subscribers only.Follow @Brexit for all the latest news, and sign up to our daily Brexit Bulletin newsletter.Why is Britain’s foreign secretary, Boris Johnson, in a fight with the country’s statistics chief?