Unit Three. The legal sources of EU law

Step 1. Overview

We have already discussed that EU law is made possible by the limited transfer of powers by Member States to the EU. Hence, the EU institutions can adopt legislation and act on behalf of Member States in all areas of exclusive EU competences, and in some areas of shared EU competences.

But how does this happen in practice? First, Member States established their Community (and later the EU). This happened through the adoption of the EU treaties, which gradually increased the powers of the EU. The Treaties also established and reformed the EU institutions. EU Treaties are part of the “primary EU law”. You can imagine primary EU law as a sort of constitutional legal setup of the EU. However, the EU does not have a proper EU Constitution, since the draft Constitutional Treaty was not finally ratified by Member States. Primary EU law also includes the international agreements concluded by the EU.

Now read more about the history of the key EU Treaties.

Based on the EU Treaties, the EU institutions draft and adopt EU legislation. This legislation is also called “secondary EU law”, because it stems from the primary EU law. Secondary EU law contains specific rules in different policy areas. Secondary EU law can only be adopted where specific powers have been transferred by the EU Member States to the EU. This is very important – the EU never acts outside of its limited competences!