Yes, I would say P. violaceusmale too. Males often have this greenish colour. There aren't similar large species in SW France, only P. pusillus, which considerably is smaller and with a different habitus.
P.violaceus was my first guess because on same tree, with the Chrysididae, several times I saw also big Pemphredon (probably lugubris) which is host of violaceus.
Nice shots! Its a Pseudomalus (very deep scapal basin and the mesopleuron has this "out-turned" ... From the quite long hairs, and moderate size, and colour it could perhaps be P. violaceus unless there are more species with these characters in the area. Paolo should ...
This is a beautiful male of Pseudomalusviolaceus(Scopoli). It is often green to greenish or green-bluish, in contrast with the violet or bluish colour of the females.