According to a BBC reporter

The pound dips on this with cable falling from 1.3220 levels to a low of 1.3208 before coming back up now to 1.3220. Looking at price action in the pound now, I must say that it has a sense of a lack of liquidity given the kind of gyrations we're seeing over the past few hours.

After jumping up to 1.3330 earlier, it has been a quick trip back towards 1.3220 now which is basically a depiction of the mess we've been seeing in the daily chart this week as well.