40In the fourth place, it is important to state that where an obligation imposed on Member States may have financial consequences for them, that obligation must be sufficiently clear and precise, in order to enable them to understand its scope and comply with it. In accordance with settled case-law, the principle of legal certainty, which forms part of the general principles of EU law, requires that rules of law be clear, precise and predictable in their effect, so that interested parties can ascertain their position in situations and legal relationships governed by EU law (see judgment of 5 May 2015, Spain v Commission, C‑147/13, EU:C:2015:299, paragraph 79 and the case-law cited).