Regarding the narrower legal use of the concept, it is quite clear that lack of proportionality can be invoked as a ground for impugning particular legislative or administrative measures of the European Union, or national measures of the Member States which implement European law.
However, the intensity of judicial review on this basis will typically be low, since for measures which entail policy decisions or involve complex assessments of the technical and economic situation, the courts will recognize a wide margin of appreciation to the legislative or administrative authorities and only overturn a measure if they consider that this is ‘manifestly inappropriate’.