on a holly leaf
No interactions present.
These two families can be similar and are distinguished by wing venation which I can't see clearly, though you may well have - agreed it does look like an ichneumon. Also, do you have a size estimate? (from the leaf it looks quite small).
My error - I should have put Ichneumonoidea.
Lat/Lng: 50.861753, -1.614294
OS grid ref: SU272069