Professor of Constitutional Law at the Aristotle University of Thessaloniki.
Deputy Prime Minister and Minister of Foreign Affairs of the Hellenic Republic (2013-2015). Leader of PASOK (2012-2015). Deputy Prime Minister and Minister of Finance (2011-2012). Minister for National Defense (2009-2011). Minister for Press and Mass Media- Government Spokesperson (1993-95), Minister for Transport and Communications (1995-96), Minister for Justice (1996), Minister for Culture & Sports (1996 – 1999), Minister for Development, Energy, Industry, Trade, Tourism and Technology (1999-2000), Minister for Culture & Sports 2000-2004 (in charge of coordinating the entire range of aspects of the Athens 2004 Olympic Games preparation). Member of the Greek Parliament (1993-2019).
General Rapporteur for the revision of the Greek Constitution (1995-2001)
Rapporteur of the Parliamentary Assembly of the Council of Europe for the implementation of the judgments of the European Court of Human Rights (2017-2019).