A former member of the UDF himself, Sofianski left the party following its fall from power after the June 2001 general election to form his own party, the Union of Free Democrats.
Sofiyanski, i sam bivši član UDF, napustio je stranku nakon što je izgubila vlast na općim izborima u lipnju 2001., i ustrojio vlastitu stranku, Uniju slobodnih demokrata.