Following the decision of four Catalan political prisoners to go on hunger strike (Report, theguardian.com, 4 December), we write to draw attention to the plight of many others who remain under the radar of international attention. As academics in the fields of political science, law and other disciplines, we are particularly concerned about the decision by the Spanish judiciary to prosecute two political science scholars and two law scholars based at three different universities in Barcelona. The four academics, (Jordi Matas, Tània Verge, Marc Marsal and Josep Pagès) along with a lawyer (Marta Alsina) were appointed members of the electoral commission in September 2017 by the parliament of Catalonia to monitor the 1 October 2017 referendum.

Even though the Spanish constitutional court forced them to resign through fines of €12,000 per person for each day that they remained in their position, the Spanish judiciary has charged the electoral monitors with the offences of “disobedience” and “usurpation of functions” and they are facing the very real possibility of up to two years and nine months in prison.

It is probably the first time in the history of the EU that political scientists and lawyers are being threatened with a prison sentence for using their expertise to guarantee that a referendum is held in a fair and impartial way. In doing so, they acted at the request of the parliament of Catalonia, which had a valid legal mandate at the time.

While we do not take a position on the question of Catalonia’s independence in this letter, we are indignant over the prosecution of our colleagues and demand the immediate removal of the threat of a prison sentence and the dropping of all criminal charges against them.

Monica Clua-Losada University of Texas Rio Grande Valley, USA, David Whyte University of Liverpool, UK, Noam Chomsky MIT, USA, Yanis Varoufakis University of Athens, Greece, Alain-G Gagnon Université du Québec à Montréal, Canada, Jane Mansbridge Harvard Kennedy School, USA, Fiona MacKay University of Edinburgh, Scotland, Bart Maddens Catholic University of Leuven, Belgium, Meryl Kenny University of Edinburgh, Scotland, Angela Wilson On behalf of the Political Studies Association of the United Kingdom, UK, Lars-Erik Cederman ETH Zürich – International Conflict Research, Switzerland, James Galbraith University of Texas at Austin, USA, Jill Vickers Carleton University, Canada, Mona Lena Krook Rutgers University, USA, Shirin Rai University of Warwick, UK, Joan Ramon Resina Stanford University, USA, Pablo Beramendi Duke University, USA, Carles Boix Princeton University, USA, Louise Chappell University of New South Wales, Australia, Sarah Childs Birkbeck College, University of London, UK, Klaus Detterbeck Universität Göttingen, Germany, Mario Diani University of Trento, Italy, David Farrell University College Dublin, Ireland, André Freire ISCTE-IUL, Lisbon, Portugal, Jonathan Hopkin London School of Economics and Political Science, UK, John Kincaid Lafayette College, USA, Joni Lovenduski Birkbeck College, University of London, UK, Shirin Rai University of Warwick, UK, Joan Ramon Resina Stanford University, USA, Birgit Sauer Universität Wien, Austria, Michael Saward University of Warwick, UK, Klaus Stolz Technische Universität Chemnitz, Germany, Wilfried Swenden University of Edinburgh, Scotland, Linda Trimble University of Alberta, Canada, Ingrid Van Biezen Leiden University, Netherlands, Mieke Verloo Radboud University, Netherlands, Georgina Waylen University of Manchester, UK, Paul Webb University of Sussex, UK, and more than 400 others (full list of signatories at tinyurl.com/y8k3yc4b)

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