For the AG, Article 3 (2) TFEU lays down additional grounds for EU
exclusive competence other than the express exclusive powers in Article 3 (1) TFEU and therefore that «competence must -LSB-...] stem from some other basis than the Treaties themselves» (para. 353).
Next, the Court had to determine whether the amendment was confined to Part Three of the Treaty and thus had to establish whether it improperly encroached upon
other EU policies outside of Part Three, namely the EU's
exclusive competence over monetary policy and the power to coordinate economic policy, enshrined in Part One TFEU.