This chapter aims to analyse whether and, if so, why the jurisdiction of the Court of Justice of the European Union supports the European Parliament’s decision-making powers in the European governance system since the entry into force of the Lisbon Treaty. While the Court has historically played a role in empowering the Parliament, some arguments support the idea that this support has declined since Maastricht, and even more in the post-Lisbon period. Through the case study of the Court’s case law on the external powers of the Parliament, we see that (1) there is no systematic bias in favour of the Parliament in the Court’s case law; (2) the Court may still be supportive of the Parliament, in particular when it also develops its own jurisdiction over European law and helps strengthening the European legal order.