Marek Pastuszko graduated from Law and Administration Faculty at the University of Warsaw and from postgraduate studies on European Substantive Law at the University of Finance and Management in Warsaw. A legal counsel since 1997.

In years 1991-1999 Marek Pastuszko worked at Towarzystwo Ubezpieczeń i Reasekuracji Polisa S.A. and Towarzystwo Ubezpieczeń na Życie Polisa S.A. (insurance companies), inter alia, as a General Specialist of property and financial insurance and as a Director of Law and Organization Department. In years 1999-2000 he worked as a legal counsel at PTE Kredyt Banku S.A. (General Pension Society), then in years 2000-2001 as a legal counsel at the law firm Hunton & Willliams, T. Kacymirow, J. Michalski, Z. Mrowiec. During years 2001-2002 Marek Pastuszko worked in Telekomunikacja Polska S.A. as a Director of Legal Department. In years 2003-2006 he was hired in Art Marketing Syndicate S.A. as a legal counsel and Coordinator of Legal Department. Between September 2006 and December 2008 Marek Pastuszko worked in PGE Polska Grupa Energetyczna S.A. as a Director of Law Section at the Organisation Department and as a Task Manager of the IPO Project. In addition, between October 2006 and July 2008 he was the President of the Management Board at PGE Energia S.A. Subsequently, in years 2009-2010 he worked as a legal counsel at the international law firm Bird & Bird. Since May 2010 Marek Pastuszko has held a position of Deputy Director of Legal Department at the Gas Transmission Operator GAZ-SYSTEM S.A.

Marek Pastuszko was also a Supervisory Board member in PSE-Operator S.A., Agencja Rynku Energii S.A., BOT Górnictwo i Energetyka S.A. and PGE RZE Dystrybucja S.A.