Confidence: It's likely to be this, but I can't be certain.
Notes: Identification thanks to Dr John Noyes, chalcidoid expert at the NHM. He says: 'Looks like a species of Philotrypesis (or close) to me. ... Was picture taken in France or around the Mediterranean? The genus gets as far up as mid France.' Is the locality correct for this or might it have stowed away in your luggage following a holiday in the Med?