OLDHAM, ENGLAND - NOVEMBER 6: Labour party leader Jeremy Corbyn (C) and Deputy Leader Tom Watson (R) alongside Labour candidate Jim McMahon during a launch event at the party's campaign centre on November 6, 2015 in Oldham, England. Following the death of the Labour MP and former Shadow Cabinet member, Michael Meacher, who held the seat since 1997, a by-election will be held in the Oldham West and Royton Constituency on December 3.  (Photo by Dave Thompson/Getty Images)