Simeon Saxe-Coburg-Gotha
Kostov and the DSB are outspoken opponents of the Bulgarian Socialist Party whom they regard as the heir to the totalitarian Bulgarian Communist Party and define them as their main political enemy. They have also often criticized ex-Prime Minister Simeon Saxe-Coburg-Gotha for allying himself with the socialists and who is accused, very much like Kostov was, of corruption.