Willow Warbler (Phylloscopus trochilus)

One of the first birds I saw this morning was a Warbler flitting about among the flowers on the Cherry.  Grab the camera, I am learning I had fitted the telephoto last night ready for birds in the morning!  

Warblers are notoriously difficult unless you hear them call or have them in the hand.  After much looking at my shots and Clickychick's I have decided it is probably a Willow Warbler.  My reasoning goes like this:
WW are long distance migrants and have long primary feathers, longer than Chiffchaff.  The legs are pale(ish) more usual in WW than Chiffchaff and the supercilium is more prominent than I am used to in Chiffchaff.

This is another species which has sadly declined since the 60s now being about 1/3 of what was around in the mid 60s.