Sitting in his cramped office in the heart of the picturesque Dordogne village of Verteillac, Bruno Merlaud smiles. Behind him is a box of teabags featuring a union flag and the words Keep Calm and Carry On. “Keep this under your hat. I would say that one in 10 Britons are twits. That compares with nine out of 10 French. Now there are fewer of you, it makes me sad. They are a clientele I appreciate enormously,” he says.