He has been serving as the European Commissioner for Internal Affairs and Migration since 2024, where he oversees EU policies on migration, border management, internal security, and cooperation among law enforcement authorities. In this capacity, he works to strengthen the EU’s security frameworks, ensure the protection of fundamental rights, and coordinate cross-border responses to migration and security challenges.

Prior to his current role, Brunner held several senior political and governmental positions in Austria. He was Federal Minister of Finance from 2021 to 2024, State Secretary in the Federal Ministry for Climate Protection, Environment, Energy, Mobility, Innovation and Technology in 2020–2021, and Vice-President of the Federal Council from 2018 to 2020. 

He is Minister of Migration and Asylum, Member of Parliament for Athens A, and a lawyer. His work includes participation in parliamentary committees related to criminal liability of ministers, educational affairs, parliamentary ethics, social security, and the monitoring of the social security system.

Since 2019, he has served as a Member of the Hellenic Parliament for the Athens A district with New Democracy.

He holds a law degree and a doctorate from the University of Athens, and a postgraduate degree from the University of Heidelberg (2002), focusing on patient consent in Greek and German criminal law. 

He holds a PhD in Public International Law from the University of Bristol (2017). During the academic year 2017-2018 he was a Nippon Foundation Fellow at the International Tribunal for the Law of the Sea in Hamburg. He graduated from the Law School of the Aristotle University of Thessaloniki and received a Master’s degree (LLM) in Public International Law from the University of Bristol.

He has taught Public International Law, International Humanitarian Law and European Law at academic institutions in Cyprus and abroad. He was a legal advisor to the Ministry of Foreign Affairs on Public International and European law issues. He has represented the Republic of Cyprus at the International Court of Justice in The Hague and in working groups of the Council of the European Union.

In 2019 he was awarded by the Hellenic Society of International Law and International Relations for the best doctoral thesis in international law for the years 2017-2019. In 2020 he was awarded by the International Association for the Law of the Sea for an academic article published in an international legal journal. He has published a book (a second one is currently under publication) and several academic articles/chapters in international legal publications. He has served as Chairman of the International and European Law Committee of the Cyprus Bar Association. 

He is the General Director and legal representative of SYNYPARXIS. He holds a bachelor’s and master’s degree from the Department of Social Theology of the National and Kapodistrian University of Athens, and in 2019 he was awarded a doctorate with honors from the Pontifical Institute of Oriental Studies in Rome with a thesis entitled: “The Ravenna Text (2007): Analysis-Critical Review.”

He has been in the position of General Director of the organization since 2017, having successively assumed, since 2016, following relevant decisions of the Permanent Holy Synod, the position of member of the Executive Committee, Head of the organization, and associate of the Special Synodal Committee on Migrants, Refugees, and Returnees. With its decision no. 4758/22.11.2019, the Permanent Holy Synod further entrusted him with representing the Church of Greece on migration and refugee issues before Greek and European institutions and organizations.

He is fluent in Italian and English, is a member of national and European networks for the support of refugees and asylum seekers, and has participated in numerous relevant conferences and workshops as a speaker. In addition, he has authored books, studies, and articles on theological, liturgical, and historical topics, as well as on issues related to migration and refugees. In addition to his duties as General Director of SYNYPARXIS, he is Secretary of the Synodal Committee on Finance of the Church of Greece and Preacher of the Holy Metropolis of Nea Ionia, Philadelphia, Heraklion, and Chalkedon, where he has served since 1997.