Watch the London mayor unable to remember the candidate for the Clacton by-election which Ukip defector Douglas Carswell is set to win ...http://telegraph.feedsportal.com/c/32726/f/579309/s/3f310181/sc/7/l/0L0Stelegraph0O0Cnews0Cnewsvideo0Cuk0Epolitics0Evideo0C111455590CBoris0EJohnson0Efails0Eto0Ename0ETory0Ecandidate0Ein0EClacton0Eby0Eelection0Bhtml/story01.htm