U-tailed Mottle Tipula confusa
The U-shaped sternite on the underside of the males' abdomen seems to be a very distinctive character in this species.
male U-tailed Mottle Tipula confusa showing abdomen from side (with close-up of tip), 8th sternite, head from below and wing, Wendling Beck Environment Project (Norfolk, UK), 8th October 2023