Mayor of Sofia Srefan Sofiyanski, former interim Prime Minister in 1997, appealed the executive body of Union of Democratic Forces must resign and Prime Minister Ivan Kostov should step back with dignity. `I appeal it not as a mayor, just as a regular party member.`, he added. President Stoyanov commented that `UDF already has a civilized procedure in such cases, established in 1994`. In that year former PM Philip Dimitrov resigned after heavily losing the elections. UDF executive body did not comment the news, they invited mayor Sofiyankski at a special meeting to explain his appeal.