Iains I don't need to nitpick with the graph. The graph tells it all for everyone to see.

Immediately after the Brexit vote the pound slumped against the Euro (and the Dollar) it has not, as yet, recovered.

It has persistently traded at less than 10% against the Euro of it's previous value.

(I've used this figure so you cannot argue semantics about precise rates)

The fall was caused by one reason, and one reason only, and that was that the UK government decided to extract themselves from the EU.

Can I suggest you take another look at the exchange rates both before, during, and after the Brexit debacle.