Today was warm and sunny with just a light breeze. This brought out the insects, including this drone hoverfly.
They mimic drone honeybees so that predators will mistake them for an insect with a sting in its tail.
Drone hoverflies belong to the genus Eristalis.
The most common species in the UK is Eristalis tenax, but due to the yellow front feet I think this is Eristalis pertinax. I would be more than happy to have this confirmed or corrected by someone who actually knows this stuff though.