The bill is too small for a starling I think and judging by the background of other picture it's not a big bird as the scale of the photo's appears similar. So smallish and tit like as the bill is similar to the blue tit, definitely not finch or sparrow like, the bill is the wrong shape.
Dunnock perhaps? Or if I've got the size wrong a thrush of some sort, perhaps fieldfare by the bill?