Confidence: I'm as sure as I can be.
Notes: A glossy chafer in a garden is likely to be this. Hoplia philanthus is also glossy, but this is easily excluded because your photo clearly shows the hind feet to have two sub-equal claws. Also it is not a garden species. "Bracken Chafer" is a curious name for this insect since it occurs commonly in the absence of bracken and, near me, sometimes builds up to huge numbers on the downs.