Looks like a really pale buzzard, their plumage is very variable. But, on the other hand, I could quite easily be wrong!
Thanks. That potentially makes sense. We get buzzards, sparrowhawks and red kites regularly. It just seems very pale compared to the buzzards we normally see but too speckled for a sparrowhawk (which was what I initially thought it was before looking more closely front and back)
It's a pale morph buzzard. Some can be even whiter than this one.