EUR/GBP has broken decisively below the base of a six-week range (red dashed line on chart) and is in free fall.
The pair is likely to fall substantially lower as the bearish trend resumes. The usual technical method of determining how far, is to take the height of the prior range and extrapolate it lower. A conservative estimate lies at the Fibonacci 61.8% extrapolation, at 0.8225.
A more optimistic forecast at the 100% extension, at 0.8171.