This work is in the public domain according to Spanish Royal Act 1/1996, on April 12, about Intellectual Property, article 13,

Legal or regulatory provisions and the drafts thereof, judgements of jurisdictional bodies and acts, resolutions, discussions and rulings of public bodies, and official translations of all such texts, shall not be subject of "intellectual property"

That means that laws, resolutions and so, from the governments, parliaments and other public and official administrations of Spain, its autonomous communities and other public entities, are not eligible for copyright protection.

---

As an edict of a government, it is also in the public domain in the United States.