Found this large flying insect in Swansea South Wales.
Was approximately 4cm x 2.5cm in size.
Thought it could be a horse fly or Wasp mimic but I am no entomologist.
Any suggestion i would be very grateful.
this is a horse fly, family Tabanidae. Because of the unusually large size you mention, it would think it is most likely Tabanus bovinus, the giant horse fly.
Hope that's helpful