The prohibition of the reformationis in peius in administrative criminal law

This master's thesis deals with the modern development of the prohibition of reformationis in peius principle in the area of administrative punitive law, in particular in the area of administrative offenses. Although Act No. 250/2016 Coll. has removed the undesirable and criticized "double-track" application of the prohibition of reformatio in peius in the area of administrative punitive law, other difficulties related to the principle in question have not completely disappeared; on the contrary, new legislation has made the situation more difficult in some respect. The main aim of the thesis is to critically analyse this principle in light of the new Act No. 250/2016 Coll. and to assess the impact of the new Act on the administrative practice. The thesis is systematically divided into seven chapters. The first chapter explains general theoretical questions related to the principle in question. The following section describes its constitutional and international basis. The third chapter thoroughly examines the modern development of this principle in the Czech Republic. The content and scope of the prohibition of reformatio in peius in proceedings under Act No. 200/1990 Coll. And in proceedings under Act No. 500/2004 Coll. are being analysed with regard to the conclusions provided by legal academia..