That's quite a quick turnaround from the lows of the day around 1.2027 after the dollar was slightly bid after the hotter French and Spanish inflation numbers earlier. If you're wondering why that was the case i.e. why the dollar benefited, it was more so tied to a drop in equities, which has since eased up, and move higher in bond yields. In the case of GBP/USD, the pair also caught a bounce off its 200-hour moving average:

GBPUSD

I wouldn't pin the resilience in the pound this week on Brexit matters, even if there are positive developments to be had there. We might finally close the book on all the drama over the past few years but let's be honest, it has been nothing but noise for UK markets for the longest of time already now.

Instead, I'd argue that it is stemming more from a technical standpoint. And even with the recovery bounce above in cable, there's still a lot to be done to really break out from the sideways action in the bigger picture as highlighted earlier here.