The Institute of Self-Government Studies, a think tank under the Generalitat of Catalonia, has proposed a comprehensive reform of the Spanish Senate to address what it describes as systemic deficiencies in territorial representation.

The proposal, detailed in a study published in June 2026 in the Journal of Autonomous and Federal Studies, argues that the Senate fails to fulfil its constitutional role as a chamber of territorial representation. The article, titled '(Lack of) Territorial Representation in the Spanish Senate: Constitutional Design and Political Practice', was authored by political scientists Lorena Ortiz of the University of Leuven and Josep Maria Tirapu-Sanuy from the University of Cambridge.

Currently, only 58 of the Senate’s 266 members are appointed by autonomous communities, just 21.8%. The authors advocate for a shift so that all senators are appointed by regional executive or legislative bodies, ensuring stronger regional input into national decision-making.

The Senate's inability to function effectively as a chamber of territorial representation affects not only its legislative function but also the composition of other key institutions.

This includes the Constitutional Court, whose legitimacy the authors argue is undermined by the current system. They note that the Senate plays a formal role in appointing judges to the Court, intended to reflect Spain’s territorial structure. But with weak regional representation in the Senate, this principle remains unfulfilled.

The study highlights that the People's Party's long-standing dominance in the Senate has influenced its approach to decentralisation, calling it 'a complex relationship with territorial decentralization' that has shaped senatorial activity for decades.

Constitutional Implications

The researchers warn that flawed territorial representation extends beyond the Senate, affecting processes such as constitutional reform and intergovernmental conflict resolution. When regional voices are absent from central institutions, trust erodes, particularly among autonomous communities that view the Constitutional Court as biased.

'The absence of effective territorial participation in the Court's composition can undermine the institution's legitimacy,' the paper states, citing prior rulings where the Court itself acknowledged the intent behind senatorial appointments, to integrate Spain’s territorial diversity into judicial oversight.

Political Hurdles Acknowledged

The authors concede that their proposal amounts to a 'substantial reform, which would be difficult to carry out' given the high thresholds required to amend the Constitution. No political party currently holds enough support to advance such changes without broad consensus.

The study appears in a monographic issue of the journal focused on second chambers in federal systems, hosted by RACO (Revistes Catalanes amb Accés Obert), the open-access platform of Catalan universities (Vol. 43, No. 43, 2026).

Primary sources: Josep Maria Tirapu. Reported by elconfidencial.com, raco.cat, Josep M. Tirapu-Sanuy, Dave Guénette, Félix Mathieu, El Confidencial.