My best guess is that this is Theridion sisyphium, though it might be another species in the genus (impressum, maybe, or pictum).
No interactions present.
I think the comments you've given are correct. My understanding is that sisyphium can't be distinguished with certainty from impressum from a photo (so Theridion sp. would be a safer ID)
Lat/Lng: 51.3802, 1.39741
OS grid ref: TR365700