This thesis intends to provide some insights into the substantive, organizational and procedural segments of the process of Europeanization of public services that is being brought into national legal systems and practices of public authorities, regarding their decisions on the definition of which public services they wish to render available to their citizens and on the means they wish to use to provide these services. The thesis is tied together throughout its various strands by a main idea that comprises a twofold assumption. Firstly, the discharge of the social democratic mandate, by political public authorities, when they define the general interest requirements to be pursued in the provision of certain public services, is and can not be per se under Community scrutiny. Secondly, however, it is only the 'exercise' of that social democratic mandate that may be under Community scrutiny, to the extent that such authorities choose a non-market solution as a way to cope with the social needs of their citizens’ community, i.e., in case they regard it as 'necessary' to restrict or exclude economic freedoms and/or competition in the market concerned, in order to enable the [socially desired and politically defined] general interest requirements to be secured, through the provision of public services, and by doing so public authorities can fully comply with their social democratic mandate. The main focus then lies on the political choices as to the level of social welfare, quality and other general interest service specifications that market fails to provide in a satisfactory manner, and will then justify the need to choose a non-market solution to enable such services to be rendered available to social communities, although with restrictions to competition or to economic freedoms. Moreover, in case the non-market solution also entails the need to arrange funding mechanisms that depart from normal market-functioning, a 'transparency frame', in particular, set out by Altmark conditions and the recent legal regime build up on it, must be respected.