51It is true that there may be great differences in the types of obligations which directives impose on the Member States and therefore in the results which they must achieve. It is also common ground that provisions of a directive which concern only the relations between the Member States and the Commission may not require to be transposed (see, to that effect, Case C-32/05Commission v Luxembourg [2006] ECR I-11323, paragraphs 35 and 36). That is however irrelevant for the outcome of the present dispute. It cannot be denied that Articles 9 and 11 of Directive 2003/87 govern the respective roles of the Commission and the Member States in the context of the procedure for adoption of the national allocation plans, that is to say the allocation of powers between them. Those provisions make it possible to determine whether the Member States enjoy a margin for manoeuvre when drawing up their plan and, as the case may be, what is the scope thereof.