This article explores the relationship between EU internal market law and ambitious tobacco end-game policies, using the United Kingdom's proposed smoke-free generation measure and its application to Northern Ireland under the Windsor Framework as a focal case. Responding to objections raised by EU Member States through the Technical Regulations Information System (TRIS), the article develops an interpretative framework that situates free movement rules within the EU's broader constitutional commitment to public health protection. Drawing on a doctrinal analysis of EU primary law, the Tobacco Products Directive, EU Court of Justice case law, and the TRIS submissions themselves, the article challenges claims that generational sales bans are inherently incompatible with EU law. It argues that such claims rely on narrow and selective readings of internal market doctrine that overlook the extent to which health protection is embedded in EU market regulation. The analysis demonstrates that EU law leaves significant regulatory space for national authorities to pursue proportionate, evidence-based tobacco control measures, including end-game strategies. Beyond the immediate UK-Northern Ireland context, the findings have broader implications for innovative public health regulation within the EU, contributing to ongoing debates at the intersection of health policy, regulatory governance, and economic integration.