Every PPL can fly VFR without sight of surface, worldwide.
Unless his license says he cannot (and UK issued ones do). No other European country
AFAIK has such a limitation on its PPLs.
However if the UK PPL gets an IMCR or an IR, this restriction falls away and he can now fly VFR without sight of surface worldwide.
My understanding is that the UK PPL holder can still fly VFR on top - if he / she "has sight of the ground" - and that could well be a mountain or hill, or hole in the cloud which is 100 miles away.