For the last couple of years, one of the most common questions raised at the end of long City lunches over the port and cigars (just kidding, over the mint tea) has been: So, what would you choose, Brexit or Corbyn?

You know the arguments: Brexit would be bad but not as bad as Labour leader Jeremy Corbyn as prime minister; yet leaving the European Union would be forever, while Corbyn could be turfed out at the next election; and maybe Corbyn would not be that bad anyway.