There is a copy of the Financial Times wedged under the locked door of John McDonnell’s Westminster office. One might expect the man who could become Britain’s first socialist chancellor of the exchequer to be combing through something more radical.

But before I can ask whether he has changed his outlook on the capitalist system he so famously vowed to overthrow, McDonnell unlocks the door and unceremoniously kicks the paper in question into a dark corner of his office.