Well, it is certainly a good'un and we would never have id'd it. I knew it wasnt quercana!
Please see here for the answer....
Last night had -
0464 Diamond-back Moth (Plutella xylostella) 1
0874 Blastobasis lacticolella 1
1631 December Moth (Poecilocampa populi) 12
2264 Yellow-line Quaker (Agrochola macilenta) 1
15 moths of 4 sp.