Many thanks for clearing up the mystery for me
I searched for the Synanthedon hylaiformis, but it threw up no further info? but I did find Synanthedon scoliaeformis, which is, apparently called the the 'welsh clearwing' looks identical to the one I saw. I must admit to having a love for moths, but have never seen one of those before.
It doesnt help that I mixed up two names it should say Synanthedon tipuliformis