International Treaties in the Spanish Legal System
The Constitution as the Source of Law
1.1 Integration into the Spanish Legal System
International treaties, agreements by which the state assumes international obligations, become part of domestic Spanish law upon official publication in the Boletín Oficial del Estado (BOE). This automatic inclusion mechanism requires no adaptation law. Once published, the treaty becomes a binding national rule, observed by all state organs and applied by judges in relevant cases.
Treaties also possess passive legal force, meaning they cannot be modified domestically but only through international legal procedures. In case of conflict, treaties enjoy primacy over domestic law. However, only treaties under Article 94.1 of the Constitution hold the force of law; those under Article 94.2 lack active force and cannot amend existing statutes. Thus, conflicting laws are not unconstitutional but superseded by the treaty. The challenge lies in selecting the appropriate rule for each case.
1.2 Treaty Procedures
The Spanish State, holding exclusive competence in international relations, acquires international obligations through treaties. Autonomous Communities lack this capacity.
Consent for a treaty is given by the Minister of Foreign Affairs or a designated representative during negotiations. The King, endorsed by the President or the Minister of Foreign Affairs, ratifies the treaty. Significant treaties, such as those of a political or military nature, affecting territorial integrity, fundamental rights, or public finances, or requiring legislative changes, necessitate prior parliamentary approval.
1.3 Treaty Classifications
Classic or Traditional Treaties
These treaties incorporate international rules agreed upon by Spain with other sovereign states or international organizations into domestic law.
- Ordinary Treaties: Concluded by the government, requiring notification to Congress and Senate.
- Treaties of Particular Importance: These include treaties of a political or military nature, affecting territorial integrity, fundamental rights and duties, involving financial obligations, or requiring legislative measures. They require prior parliamentary approval.
Unique Treaties
These treaties transfer competence to supranational bodies, requiring a transfer of sovereignty. Authorization for such treaties requires an organic law (approved by an absolute majority in Congress and a simple majority in the Senate).
1.4 Constitutional Control of Treaties
International treaties are subordinate to the Spanish Constitution. Their constitutionality is subject to the following controls:
- Preventive Control: Before state consent, the Constitutional Court can review treaties for potential conflicts with the Constitution. A prior constitutional revision may be necessary.
- Post-Clearance Control: After conclusion and publication, treaties can be challenged before the Constitutional Court via a constitutional motion within three months or by a judicial body raising unconstitutionality concerns.
A declaration of unconstitutionality can impact foreign policy and international relations, potentially requiring diplomatic efforts to modify or waive the treaty.