Although there are several similar species Ichneumon suspiciosus is one of the most common so applying my rule that I am statistically more likely to see a common species than a rare one I am going for suspiciosus. It has the half brown/half black abdomen, the orange legs and the yellow triangle just behind the head all of which tie in, I believe.
Ichneumons are parasitic insects and lay their eggs in the body of the larva of another creatures, moth caterpillars are the host of many including this species; the female ichneumons have a long sharp ovipositor for this very purpose. They are related to bees and wasps and that long ovipositor could be mistaken for a sting but, in general, they are harmless to humans although they can look pretty fierce!
Ichneumon suspiciosus: is very common on umbel flowers, especially hogweed, in summer and, unusually perhaps, the adult overwinters by hibernating just like queen bees and wasps
Ichneumon suspiciosus: an ichneumon fly