There were several surprises in George Osborne’s sixth autumn statement as chancellor of the exchequer, but the announcement that grabbed the headlines was the (temporary) reversal on cutting working tax credit. For some commentators, that volte face, and the chancellor’s performance more broadly, was a display of unparalleled acumen. Here was a politician, they purred, at the top of his game, an exponent of statesmanship who could seize the centre ground while almost issuing an apology. For others, including the shadow chancellor, John McDonnell, Osborne’s offer was a political capitulation of the first order, a premier cru bottlejob by a champagne charlie. The truth, unsurprisingly, is somewhere in between, but what shouldn’t be overlooked is Osborne’s ambition for the top job.