The Catalan Referendum on Independence: A Constitutional Conundrum

Sabrina Ragone
December 20, 2017

The consequences of the referendum on independence, held in Catalonia on October 1, 2017, have given rise to a broad debate and are still to be assessed in their entirety. In fact, the vote was just the last of a decade-long series of moves by the Catalan government and parliament, and counter-moves on the Spanish side,[1] putting the Spanish democracy and all of its branches of government under stress as never before in its recent history.

This Insight discusses the constitutional and political context in which these events have taken place, highlighting the role played by the executives, the legislatures, and the Constitutional Court. It focuses on the main issues raised in scholarship and the media: the constitutional uniqueness of Catalonia, the importance of the Constitutional Court in the management of the conflict, and the legality of the instruments that Catalonia used to pursue its independence.  

Has Catalonia Always been “Constitutionally Different”?

Catalan autonomy is not new. As early as the second Republic (1931–1939), Catalonia, along with the Basque Country and Galicia, passed their statute of autonomy as authorized by the 1931 Constitution. However, political centralization soon returned under Franco’s dictatorial regime (1939–1975).

When the current Spanish Constitution entered into force in 1978, it offered a special or fast track to autonomy for the regions of Catalonia, the Basque Country and Galicia. For the rest of the territory, the Constitution offers an ordinary or slow track, through which provinces (local authorities) could jointly create an autonomous community entitled to legislative, executive, and administrative powers.[2] Both tracks require the autonomous parliament and the Spanish parliament to approve a statute of autonomy containing all relevant provisions concerning institutions and devolved legislative matters. Special autonomous communities were allowed to assume jurisdiction for the entire list of legislative matters that may be devolved to subnational entities when passing their first statute of autonomy in the late 70s and 80s. Ordinary communities had to wait for five years after approval of their first statute of autonomy to align their legislative jurisdiction to the special ones.

Seventeen autonomous communities were thus established, including four special communities: Catalonia, Basque Country, Galicia, and Andalusia.

From Autonomy to Self-Determination? The 2006–2016 Decade

By the early 2000s, all communities had achieved similar levels of legislative autonomy. At that point, new efforts for wider autonomy started with the “Plan Ibarretxe,” a reform of the Basque statute of autonomy based on self-determination of the “Basque people.” That reform failed after it was rejected by the Spanish parliament in 2005.

Just one year later, a reform of the Catalan statute was passed by the Catalan parliament and the Spanish parliament. However, the conservative Partido Popular (PP – Popular Party), which had opposed the reform in the Catalan parliament, challenged the statute before the Constitutional Court, arguing that it subverted the basis of the territorial organization of the state. The PP contested all Catalan identity components of the statute, such as the definition of a Catalan people and a Catalan nation, the preferential use of Catalan language, the recognition of the historical difference of Catalonia, and the regulation of rights and principles applicable only in Catalonia. Four years later, the Constitutional Court issued judgment 31/2010,[3] which represented a point of no return in the Catalan struggle for independence. The judgment, while ostensibly reinterpreting the Catalan identity claims through a constitutional lens, in fact eviscerated the statute from its purpose.[4]

Protests in Catalonia and changes in parliamentary majorities in Barcelona and in Madrid followed. In 2010 the nationalist force Convergence and Union (CiU) achieved a relative majority (62 out of 135) in the Catalan parliament, and its leader, Artur Mas, became president. In the 2012 snap elections, CiU fell to fifty and formed a coalition with the Republican Left. This event changed the political equilibria in Catalan politics.

Meanwhile, the Popular Party, which traditionally opposes separatist claims, obtained the majority in the Spanish elections at the end of 2011 and Mariano Rajoy became the Prime Minister. He has kept the post since then.

In 2012, the new Catalan parliament approved a “Declaration of sovereignty,”[5] triggering a more acute conflict with Spanish institutions. The Declaration dubbed the 2010 judgment a sweeping denial of Catalonia’s right to self-determination. The Spanish government led by the PP challenged the Declaration before the Constitutional Court, which found the Declaration’s sovereign assertions to be unconstitutional.[6] In particular, the Court ruled that defining the Catalan people as a politically and legally sovereign body infringed upon the principle of constitutional primacy and the unity of Spain.

Catalonia first moved on a vote for independence in November 2014 with a “popular consultation,”[7] but the process was suspended by the Constitutional Court. The Catalan government organized a non-official and non-binding vote instead. Participation was approximately 35 percent of eligible voters, with 80 percent favoring independence. Nonetheless, in the September 2015 elections, the main pro-independence forces failed to garner an absolute majority in the Catalan parliament and had to seek the endorsement of anti-capitalist and separatist party Popular Unity Candidacy (CUP). The latter required the appointment of a new president of Catalonia (Carles Puigdemont).

The new Catalan parliament purported to assume the sovereign representation of Catalan people in the process of leaving Spain through a constitutional process.[8] The Constitutional Court was again brought into the arena and issued, in December 2015, a judgment defending the unity of Spain and its sovereignty.[9] The Catalan government later created a committee charged with drafting a constitution, in direct defiance of the Constitutional Court’s prohibition.[10]

In response, the Spanish parliament passed an amendment to the regulation of the Constitutional Court[11] providing it with stronger powers in case of non-compliance with the judgments, including issuing fines and suspending actors responsible for non-compliance.[12]

In 2017, Catalan authorities unilaterally set a referendum for October 1, when it was held despite a suspension order from the Constitutional Court. The question was whether voters wanted Catalonia to become an independent republic. Over 90 percent of voters said yes, but the final count is disputed, as several polling stations were closed down and the voting computer programs blocked by the police following judicial orders.

The Spanish government reacted by invoking, for the first time ever, the extraordinary powers of Article 155 of the Constitution (on “State coercion”), allowing the state to compel autonomous institutions to obey the law, by any means necessary. Aiming to reestablish the rule of law, Spain removed the president of Catalonia and his government from their posts and dissolved the parliament, calling for new Catalan elections to be held on December 21.

Overall, there has been no political dialogue between the Spanish and the Catalan government. While initial demands from Catalonia were mainly economic and fiscal, this lack of dialogue contributed to a pivot towards identity claims that would require a political solution.

Was the Referendum Illegal?

Catalonia’s power to seek referenda is limited to matters devolved to the autonomous community—from which independence is excluded.[13] The alternative procedure of popular consultation that was used in 2014 is equally unavailable as the means to purse independence.[14]

The Spanish Constitution does provide for referenda initiated by the central government,[15] but many scholarly commentators agree that such a consultative process must engage the entire Spanish population. A 2014 bill proposed by Catalonia seeking to transfer the government’s referenda power to Catalonia was rejected by more than 80 percent of the votes in the Spanish parliament. Even if the government authorized a regional referendum, constitutional jurisprudence does not allow referenda on the unity of Spain. Similar conclusions were reached in Italy when Veneto called for a referendum on independence[16] and in Germany concerning Bavaria.[17]

The most effective solution would be a constitutional amendment under Article 168 (“total reform”) changing the provisions on the territorial unity of the State and/or introducing a clause allowing territories to decide on their belonging to Spain.[18] The Constitutional Court has repeatedly stated that all political objectives are legitimate so long as they are pursued through constitutional means. Proponents of Catalan independence have never sought such an amendment, likely due to its low probability of success.

More generally, involving the Constitutional Court has become a trend, if not a strategy, for dealing with the Catalan issue. Since the popular consultation vote in 2014, there has been a progressive “judicialization” of the territorial conflict through an intensive involvement of the Constitutional Court, largely at the behest of the Spanish government.[19] With Catalan institutions repeatedly flaunting its judgments, the Constitutional Court suffered from a loss of authority. Furthermore, the judiciary as a whole has been brought into the conflict when criminal proceedings were initiated against the organizers of both the 2014 popular consultation and the 2017 referendum.

The decisions of the Constitutional Court closely follow the Spanish constitutional framework. From a European perspective, the rules of enlargement would require a new accession procedure for Catalonia and the unanimous acceptance of all member states.[20] From the international perspective, the main question remains the applicability of the right to self-determination to Catalonia.[21] In particular, Catalonia is not a colonial territory nor is it in a condition of subjugation, domination or exploitation. In contrast to the situation in Kosovo that led to the opinion of the International Court of Justice in 2010,[22] it is doubtful that Catalonia could be considered for a “remedial” secession, available when the domestic legal order completely prevents the exercise of the right to self-determination.[23]

About the Author: Sabrina Ragone is associate professor of comparative law at the University of Bologna, Italy. Previously, she conducted research at the Max Planck Institute for Comparative Public Law and International Law, Heidelberg, at the Center for Political and Constitutional Studies (CEPC), Madrid, and at the Autonomous University of Barcelona.

[1] See Catalonia’s Independence Bid: How did We Get Here? What is the European Dimension? What’s next?, Royal Elcano Institute (Oct. 23, 2017),

[2] Span. Const. art. 143.

[4] On these events, see Sabrina Ragone, Catalonia’s Recent Strive for Independence: A Legal Approach, in Autonomies in Europe: Solutions and Challenges (Zoltán Kántor ed., 2014), available at

[5] Resolución 5/X del Parlamento de Cataluña, por la que se aprueba la Declaración de soberanía y del derecho a decidir del pueblo de Cataluña, available at

[6] S.T.C., Mar. 25, 2014 (B.O.E. No. 87, p. 77), available at

[7] Catalan Law 10/2014 regulates popular consultations and participation, which are distinct from referenda.

[8] Resolución 1/XI del Parlamento de Cataluña, sobre el inicio del proceso político en Cataluña como consecuencia de los resultados electorales del 27 de septiembre de 2015, available at

[9] S.T.C., Dec. 2, 2015 (B.O.E., No. 10, p. 1951), available at

[10] On the events up to 2016, see the special issue of the journal Teoría y Realidad Constitucional, 37/2016, available at

[11] Ley orgánica del Tribunal Constitucional [L.O.T.C.], B.O.E. n. 239, Oct. 3, 1979 (Spain). The amendment was passed through the L.O., B.O.E n. 228, Sept. 22, 2015 (Spain).

[12] See the new article 92 of the L.O.T.C.

[13] Departamento De La Presidenciad, O.G.C. n. 5595, De Consultas Populares por vía de Referéndum, Mar. 17, 2010.

[14] See S.T.C. 103/2008, Sept. 11, 2008 concerning a law passed by the Basque parliament calling for a similar popular consultation, available at

[15] See Span. Const. art. 92.

[16] See Corte Costituzionale (Constitutional Court), 29 April 2015, n. 118 (It.), available at

[17] See Bundesverfassungsgericht [Federal Constitutional Court] Dec. 16, 2016, 2 BvR 349/16 (Ger.), available at

[18] The debate is now focusing on federal arrangement. See the document from a group of Spanish scholars, Ideas para una Reforma de la Constitución (Nov. 21, 2017), available at

[19] See Josep M. Castellá Andreu, Tribunal Constitucional y Proceso Secesionista Catalán: Respuestas Jurídico-Constitucionales a un Conflicto Político-Constitucional, 37 Teoría y Realidad Constitucional  561 (2016), available at

[20] Also, the former presidents of the European Commission, Romano Prodi and José Manuel Durão Barroso, in 2004 and 2012 respectively, asserted that the treaties would no longer apply to new independent states.

[21] On the distinction between cases of “unprivileged” secession and “privileged” secession, supported by international law, see Marc Weller, Secession and Self-determination in Western Europe: The Case of Catalonia, EJIL: Talk! (Oct. 18, 2017),

[22] Accordance with International Law of the Unilateral Declaration of Independence in Respect of Kosovo, Advisory Opinion, 2010 I.C.J. Rep. 403 (July 22), available at

[23] Anne Peters, Populist International Law? The Suspended Independence and the Normative Value of the Referendum on Catalonia, EJIL: Talk! (Oct. 12, 2017),