Confidence: It's likely to be this, but I can't be certain.
Notes: This is one of the hardest lizards to identify with any certainty unless you have it in the hand. Looking at the picture I can't see a masseteric scale (an enlarged scale between the eye and eardrum), also there is no obvious dark ocelli behind the forelimbs. The common wall lizard P.muralis would show these features and therefore I think it's most likely to be a Catalan wall lizard P.liolepis. The Catalan wall lizard is a recently described species (so it doesn't appear in many field guides yet) which was separated from the Iberian wall lizard P.hispanicus on the basis of DNA differences.