The European Union (EU) has had a Treaty competence in the field of public health since 1993, however the slow development of this competence has not kept up with the rate at which the EU's policy ambitions in public health have developed, especially in the field of non-communicable disease (NCD) prevention. This has led the EU to rely on alternative legal bases in order to realise these ambitions, leading to a 'competence gap' between the legal bases that authorise EU action on NCD prevention and the policies the EU would like to pursue. This paper will explore, in three stages, how this competence gap might be addressed. First, it will examine the arguments for and against giving the EU public health competences. Second, it will analyse the EU's specific public health competence in Article 168 of the Treaty on the Functioning of the European Union (TFEU) and the general internal market harmonisation competence in Article 114 TFEU, in order to explore the precise boundaries of each competence as legal bases for EU public health action. Third, it will explore the legal relationship between Articles 168 and 114 and explain why, despite a more powerful specific public health competence being a theoretically neat solution to the competence gap, the likelihood of the EU being given increased public health powers is low.