The flash hasn't helped - I remember it as a dark metallic moth.
The plant is Silene dioica... but it looks like it's just having a rest.
No interactions present.
I think it is a micromoth, too small for a Forester.
Thanks John, David... yes - I had forgotten about scale! It is Campion, I'm sure of that because I was measuring bits of it for my OU project at the time... which would put the moth in the micro league.
In the words of father Ted "These are very small; those are far away."
Lat/Lng: 51.67774, -0.08782
OS grid ref: TQ323993