Small shrub with large bright yellow flowers in damp, shaded patch near larger shrubs.
No interactions present.
A Hypericum but not Tutsan. One of the garden ones.
Having done some more searching of web-sites, and having seen a real Tutsan plant in a scrubby hedgerow, I now think these pictures are likely to be of a Hypericum Japonica variant.
I don't think that it's Hypericum japonicum, which Google tells me has sepals about as long as the petals.
It reminds me of Hypericum olympicum, but I don't think it's that either.
The relative length of sepals, petals and stamens is a sometimes helpful aid to identification of Hypericum.
Lat/Lng: 51.5291, -3.5027
OS grid ref: SS958822