To what extent does and should the EU internal market law limit the regulatory autonomy of its Member States? This books answers the question by exploring case law regarded as sensitive from a national point of view and assessing the legitimacy of the principles underpinning the EU constitutional order. Four case studies: healthcare, education, collective labour law and gambling, show how this autonomy works in practice. This allows the author to shine a light on constitutional imbalances. The book goes further, suggesting interpretative solutions to address these imbalances. An exciting and important new work which enhances our understanding of the limits on the internal market.