This is a Dock Bug, Coreus marginatus. It is from the family Coreidae, also known as Squash Bugs, nothing to do with squashing them, the name Squash Bug comes from North America and is a reference to the fact that some Coreidae species are pests on Squash plants.
Coreidae have four segments to their antennae.
Shield Bugs belong to the family Pentatomidae which translates from the Greek as “five sections” and Shield Bugs have five segments to their antennae.
Birch Shield Bug, Elasmostethus interstinctus.
When asked about his politics the Dock Bug said that if he won the lottery he would buy his own pumpkin patch.