The Commission sought annulment of Framework Decision 2005/667. Based on Title VI of the Treaty on European Union, in particular on Articles 31(e) EU and 34(2)(b) EU, the Framework Decision constituted the instrument by which the European Union intended to approximate criminal-law legislation of the Member States by requiring them to provide for criminal penalties in order to combat ship-source pollution caused with intent or by serious negligence.
The Commission argued that, in the light of the functional approach taken by the Court in Case C-176/03 Commission v Council  the Framework Decision as a whole infringed Article 47 EU and must accordingly be annulled.
It argued that the Framework Decision 2005/667 affected the Community’s competence under Article 80(2) EC and therefore could had been adopted on the basis of that provision.
The Court held that the Community legislature had broad legislative powers under Article 80(2) EC. The Council could decide whether, to what extent and by what procedure appropriate provisions might be laid down for sea transport and the procedural provisions of Article 71 EC were to apply. (see, inter alia, Case 97/78 Schumalla ).
The existence of the legislative competence conferred by Article 80(2) EC was not dependent on a decision by the legislature actually to exercise that competence.
It furthermore held that environmental protection must be regarded as an objective which also formed part of the common transport policy.
The Community legislature might therefore, on the basis of Article 80(2) EC and in the exercise of the powers conferred on it by that provision, decide to promote environmental protection.
The Court argued that it was within the scope of Community’s competence to impose criminal penalties.
It held that although it was true that, as a general rule, neither criminal law nor the rules of criminal procedure fell within the Community’s competence, when the application of effective, proportionate and dissuasive criminal penalties by the competent national authorities was an essential measure for combating serious environmental offences, the Community legislature might require the Member States to introduce such penalties in order to ensure that the rules which it laid down in that field were fully effective.
Since Articles 2, 3 and 5 of Framework Decision 2005/667 were designed to ensure the efficacy of the rules adopted in the field of maritime safety, non-compliance with which might have serious environmental consequences, by requiring Member States to apply criminal penalties to certain forms of conduct, those Articles must be regarded as being essentially aimed at improving maritime safety, as well as environmental protection, and could had been validly adopted on the basis of Article 80(2) EC.
On the other hand, the Court stressed that the determination of the type and level of the criminal penalties to be applied did not fall within the Community’s sphere of competence.
Therefore, the Community was not empowered to adopt provisions such as Articles 4 and 6 of Framework Decision 2005/667, since those Articles related to the type and level of the applicable criminal penalties.
Consequently, those provisions were not adopted in infringement of Article 47 EU.
The Court concluded that Framework Decision 2005/667, in encroaching on the competence which Article 80(2) EC attributed to the Community, infringed Article 47 EU and, being indivisible, must be annulled in its entirety.