Originally known as the Treaty establishing the European Economic Community, the Treaty on the Functioning of the European Union (TFEU) was created in 1958 and is commonly referred to as the Treaty of Rome.¹ The recent transformation of the TFEU occurred with the Treaty of Lisbon² in 2009, giving rise to the current TFEU.

The Treaty on European Union (TEU) emerged with the Treaty of Maastricht in 1993. Unlike the TFEU, the TEU was created to enhance intergovernmental cooperation rather than to focus solely on economic aspects.³ The TFEU and the TEU went through significant amendments with the Treaty of Amsterdam, the Treaty of Nice, and the Treaty of Lisbon.⁴ Article 1 TEU now clarifies that the TEU and the TFEU collectively constitute the foundational treaties of the Union.⁵ Nevertheless, the ToL amended the TEU to declare that the Union replaces and succeeds the Community, resulting in the removal of terms such as European Communities and Community law from official usage.⁶

The Treaties closely resemble a constitution in defining the Union's competence, its constituent parts, and the rights of its citizens.⁷ While the Treaties don't provide an exhaustive list of citizens' rights, they confer certain rights, which can be enforced directly in national courts.⁸ The Court of Justice plays a crucial role as the guardian of these rights and has consciously used the doctrine of ‘direct effect’ to empower citizens in their national courts and, if necessary, against their governments.⁹

References

1. European Parliament, “The Maastricht and Amsterdam Treaties” https://www.europarl.europa.eu/factsheets/en/sheet/3/the-maastricht-and-amsterdam-treaties accessed 18 October 2023
2. European Parliament, “Treaty of Lisbon” https://www.europarl.europa.eu/about-parliament/en/in-the-past/the-parliament-and-the-treaties/treaty-of-lisbon accessed 18 October 2023
3. Morano-Foadi, Sonia, and Jen Neller, Fairhurst's Law of the EU (Pearson International Content, 2020, 13th Edition) Available from: VitalSource, p.109
4. Ibid
5. TEU, art.1
6. European Parliament, “Treaty of Lisbon” https://www.europarl.europa.eu/about-parliament/en/in-the-past/the-parliament-and-the-treaties/treaty-of-lisbon accessed 18 October 2023
7. Morano-Foadi, Sonia, and Jen Neller, Fairhurst's Law of the EU (Pearson International Content, 2020, 13th Edition) Available from: VitalSource, p.110
8. Ibid
9. Christopher Vajda, “Democracy in the European Union: what has the Court of Justice to say?” (2015) C.J.I.C.L. 4(2), 226-241 https://uk.westlaw.com/Document/IFF6FAA30239B11E6B28DFFF455EE2E20 accessed 18 October