This is just a normal Chiffchaff (P.c.collybita) just to wind anyone up who has clicked on this post to try and catch me out- keep trying mofos :-) It's also a handy comparison to the bird below.
Here we go (found by Nick Gardner)- strong face pattern with pale super and dark eye stripe. Underparts overall white contrasting strongly with the black legs
Upperparts are greyish/buff. Some green/olive tones around carpal.