School of Law

Dr Mario Mendez, BA (Lond), LLM (William & Mary), BCL (Oxon), PhD (EUI), PGCAP (QMUL)


Reader in Law

Telephone: +44 (0)20 7882 3958
Room Number: Mile End


Mario Mendez graduated with a first class degree in Law and Politics from Queen Mary University of London and was awarded the Drapers’ Scholarship to study at the College of William and Mary in Virginia where he completed an LLM in American Legal Studies. He was awarded a distinction on the BCL at the University of Oxford and the Vinerian Scholarship Proxime Accessit. He completed his PhD at the European University Institute (EUI). He was awarded the Post-Graduate Certificate in Academic Practice at QMUL with distinction and is a fellow of the Higher Education Academy.

His research interests are mainly in constitutional law (EU, UK and comparative).  There are two main strands to his published and current research agenda and he has given evidence before Parliament (Westminster and the European Parliament) in relation to both. The first concerns the relationship between international law and domestic constitutional systems and was the subject matter of his monograph on The Legal Effects of EU Agreements (OUP 2013) and on-going research projects. The second strand concerns direct democracy and recent projects include a co-authored study on Referendums on EU Matters (2017) that was prepared for the Constitutional Affairs Committee of the European Parliament and a co-authored monograph Referendums and the European Union: A comparative inquiry (CUP 2014) (a book which has its origins in a project funded by the Swiss National Science Foundation).  

Mario has worked for the Academy of European Law at the European University Institute and has been a trainee at the European Commission. He has spent periods as a visiting academic at the University of Oxford (Institute of European and Comparative Law), University of Cambridge (Centre for European Legal Studies), the University of Michigan’s Law School, the Centre for Research on Direct Democracy at the University of Zurich.  He is a research associate at the University of Zurich’s e-Democracy centre with whom he collaborated in developing a voting advice application for the 2012 London mayoral elections. He was a lead member of the QMUL team that collaborated with the Preference Matcher consortium in developing a voting advice application for the 2015 and 2017 UK General Elections ( 

He is a former member of the editorial committee of the journal Public Law.

He is a former co-director of the QMUL Centre for European and International Legal Affairs , and a member of the QMUL Centre for Law and Society in a Global Context (CLSGC) and the QMUL Centre for European Research.

Undergraduate Teaching

  • LAW4001 Public Law
  • LAW5105 Law of the European Union
  • LAW6160 Comparative Constitutional Law.



  • Neglecting the treaty-making power in the UK: The case for change’ Law Quarterly Review (forthcoming)
  • ‘The Law and Politics of Direct Democracy in the European Union’ (with F. Mendez) in P.J. Cardwell and M-P. Granger (eds), Research Handbook on the Politics of EU Law (Edward Elgar, forthcoming 2020)
  • ‘EU Accession Referendums’ (with F. Mendez) in J. Smith (ed) The Palgrave Handbook on European Referendums (Palgrave, forthcoming 2020)
  • ‘The Application of International Law by the Court of Justice of the European Union’ in Bradley (ed) The Oxford Handbook of Comparative Foreign Relations Law (OUP 2019)
  • ‘Referendums on European Integration: Crisis-Solving or Crisis-Inducing?’ (with F. Mendez) in Morel and Qvortrup (eds) The Routledge Handbook to Referendums and Direct Democracy (Routledge 2018)
  • ‘Opinion 1/15: The Court of Justice Meets PNR Data (Again!)’ (2017) 2(3) European Papers 803 (available at:
  • ‘The Promise and Perils of Direct Democracy for the European Union’ (with F Mendez) (2017) 19 Cambridge Yearbook of European Legal Studies 48
  • Referendums on EU Matters (with F. Mendez) (European Parliament 2017) available at
  • ‘Constitutional Review of Treaties: Lessons for Comparative Constitutional Design and Practice’ (2017) 14 International Journal of Constitutional Law 84 (earlier version published as Jean Monnet Working Paper 08/16 available at
  • ‘Direct Democracy and the European Union’ (with F. Mendez) in Ruth, S., Welp, Y., and Whitehead, L (eds) Let the people rule? Direct Democracy in the Twenty-First Century, (ECPR Press, 2016) 
  • Referendums and the European Union: A comparative inquiry (with F. Mendez and V. Triga)  (Cambridge University Press 2014) (reviewed in Political Studies Review (2015: 615); EUSA Review (2014: 22); Common  Market Law Review (2015: 604)
  • The Legal Effects of EU Agreements: Maximalist Treaty Enforcement and Judicial Avoidance Techniques (Oxford University Press 2013) (available on open access at: (reviewed in Common Market Law Review (2014: 1548); Yearbook of European Law (2014: 569); Journal of Common Market Studies (2014: 1164); European Law Review (2015: 294); Legal Issues of Economic Integration (2014:211)
  •  ‘The Enforcement of EU Agreements: Bolstering the effectiveness of Treaty law?’ (2010) 47(6) Common Market Law Review 1719
  • ‘Comparing Privacy Regimes: Federal Theory and the Politics of Privacy Regulation in the European Union and the United States’ (with F. Mendez) (2010) 40(4) Publius: The Journal of Federalism 617.  
  • ‘Referendums and European integration: beyond the Lisbon vote’ (with F. Mendez) [2010] Public Law 223
  • ‘The Legal Effect of Community Agreements: Maximalist Treaty Enforcement and Judicial Avoidance Techniques’ (2010) 21(1) European Journal of International Law 83 (available at:
  •  ‘Direct Democracy in the European Union: How comparative federalism can help us understand the interplay of direct democracy and European integration’ (with F. Mendez and V. Triga) (2009) 29(1) Revista de Ciencia Política 57 (available at:
  • Passenger Name Record Agreement (2007) 3(1) European Constitutional Law Review 127 
  • ‘Introducing E-voting for the European Parliament Elections: the Constitutional Problems’ (with A. Auer) in Trechsel and Mendez (eds), The European Union and E-voting (Routledge, 2005)
  • ‘The impact of WTO rulings in the Community legal order’ (2004) 29 European Law Review 513.


Dr Mendez welcomes proposals for postgraduate supervision in the fields of UK, EU and comparative constitutional law.