4 blurry photos of what I think is the same hoverfly (there were very few about on the day).
No interactions present.
Photos 1 and 2 (on Celandine) are definitely one individual. And photos 3 and 4 are the same individual. That may not help much!
Photos 3 and 4 look to me to be Melanostoma - at a long-range guess - the other two - well?? Platycheirus
Lat/Lng: 51.349, -2.3964
OS grid ref: ST724611