ABSTRACT – In the Kinsa case, the Court of Justice is for the first time called upon to assess the validity of harmonising provisions on offences and penalties under the principle of proportionality. In his conclusions, Advocate General Richard de la Tour upholds the EU choice of criminalisation at stake; at the same time, he clarifies the implications of the principle of proportionality of criminal offences and penalties stemming from Articles 49 (3) and 52 (1) of the Charter for its domestic implementation. While being convincing on the merits, the conclusions do not offer precise indications on two key profiles, in respect of which this contribution puts forward some reflections. First, the article argues that the proportionality paradigm for reviewing harmonising provisions on offences and penalties should be conceptualised analogously to the proportionality scrutiny of national criminal measures under Articles 52 (1) and 49 (3) of the Charter. Thus, its theorisation is more complex than the requirements of appropriateness and necessity, as it involves both prospective and retrospective assessments of the constituent elements of the offence and the severity of the penalties. Secondly, the contribution argues that the assessment of the validity of supranational criminalisation choices requires strict necessity scrutiny by the Court of Justice.
