It's a shield bug nymph, perhaps Syromastes rhombeus (or a similar species).
Many thanks, Roy.
It's a Dock bug nymph - Coreus marginatus. Final instar with those wing buds.
See here: www.britishbugs.org.uk/.../coreus_marginatus.html
Rockwolf said:It's a Dock bug nymph - Coreus marginatus. Final instar with those wing buds.
That's an ID to trust over my suggestion Andrew!