Found on Quercus robur
I'm really no expert -- I've never seen examples of these -- but the Plant Parasites of Europe site is an excellent resource. From the genus of plant you can follow the detailed keys for leafmines. Alternatively, at the bottom each key there is a link to a list of all the "parasites" of that genus or its individual species, with descriptions and often photos. I find this very useful for galls, fungi, etc.
That looks a very useful site.
I think I agree it most likely is coleophora ibipennella.
It was in Notts, but I see there are records on naturespot.
All the best