The construction of the Single Supervisory Mechanism (SSM) and the whole project of the Banking Union are usually justified on the basis of the shortcomings of the institutional framework for the Single Currency, which have been so clearly exposed during the sovereign debt crisis. However, I would like to start from a different observation point, that of the Single Market. During the last three years we have witnessed a dramatic process of renationalisation of banking business, which has deeply damaged the functioning of the Single Market.[...]