In September 2017 the Parliament of Catalonia, a region enjoying autonomous status within Spain, passed legislation to enable the holding of a binding referendum on self-determination. Claiming a breach of the indissoluble unity of the Nation as guaranteed by Article 2 of the Constitution, the Spanish Government brought the law before the Spanish Constitutional Court and threatened to suspend the regional autonomy of Catalonia should the referendum be effectively held. The Court pre-emptively suspended the law, and later declared it unconstitutional and void due to both the lack of competence of the Government of Catalonia in calling a referendum on a matter of Spanish sovereign authority and the fact that its approval by the Parliament of Catalonia did not comply with voting procedures. In the weeks preceding the referendum, Spanish law enforcement authorities started to seize ballot boxes and occupy Catalan ministries to search for evidence of the breach of Spanish law. Some of the key figures of the Catalan pro-independence movement were arrested and put under accusation for sedition. Tension between the parties rose, and people started to take the streets both in Madrid and Barcelona.
On 29 September 2017, during an urgent question time taking place at the Chamber of Deputies (861st Meeting, XVII Legislature), the Undersecretary of State for Foreign Affairs and International Cooperation, Mr Vincenzo Amendola, was asked about the Italian Government’s position on the promotion of the referendum on self-determination by the Catalan authorities.
Italy's Diplomatic and Parliamentary Practice on International Law 