Legally blonde Boris Johnson s hair history. rex Credit rex. Lucy Pavia. By Lucy Pavia . A stylish timeline of the wildest tresses in parliament..It hasn t always been clear that Boris Johnson is a serious man. He has a serious job or jobs , of course, and he makes some serious .Boris Johnson. Chatshow host David Letterman cheekily asked the mayor of London how long he had been cutting his own hair when he appeared on the Late Show this week. There are eight million stories in the naked city, but not a single hairdresser in the whole of London, apparently..