One of two confusion species, this is Platycheirus granditarsus. It is usually found neary marshy fields and ditches, which is exactly where I found this one. The main field identification character is the bright orange colouration of the abdomen, which is clearly visible in flight, but completely hidden when landed.
A major differentiator between this and Xylota segnis is the expanded front tarsi (feet). Unfortunately, none of the pics I have show this detail, although the dark patches to the rear of the orange band can just be made out through the wings.