32In that regard, first of all, it should be borne in mind that the purpose of the obligation to state the reasons for an act adversely affecting a person, as laid down in the second paragraph of Article 296 TFEU, is, first, to provide the person concerned with sufficient information to make it possible to determine whether the act is well founded or whether it is vitiated by an error which may permit its validity to be contested before the Courts of the European Union and, second, to enable those Courts to review the lawfulness of the act. The obligation to state reasons thus laid down constitutes an essential principle of EU law which may be derogated from only for compelling reasons. The statement of reasons must therefore in principle be notified to the person concerned at the same time as the act adversely affecting him and a failure to state the reasons cannot be remedied by the fact that the person concerned learns the reasons for the act during the proceedings before the Courts of the European Union (judgment of 7 December 2011, HTTS v Council, T‑562/10, EU:T:2011:716, paragraph 32).