Elections of Corbyn could be just as bad for GBP as a no-deal Brexit
Labour would likely win an election
A Sunday Telegraph recently showed Labour picking up 60 seats in a general election and becoming the largest party in Parliament.
Of course, there is no election on the horizon but it's an incentive for Corbyn to grandstand on a Brexit deal and create enough chaos to force one. The downside of that is that if he won then Labour would be forced to deal with Brexit.
In any case, Citigroup told clients on Monday that a Labour win would be the equivalent to a no-deal Brexit and include a sharp drop in the pound. They conditioned that on Corbyn following through on all his pledges around banks and taxes. That's a bold assumption.
In any case, that's the kind of headline that goes into a feedback loop and spooks people who were thinking of supporting Labour. Or alternatively, it motivates people to call the bank's bluff.