PKK is not a political party it is a terrorist organization as recognized by many countries including US EU and Russia It does not declare itself on legal grounds so it can not be banned by definition Moreover by means of its organization and activities it has more of a military character rather than being political Today there is a political branch of PKK named DEHAP now transforming itself into DHT due to some internal conflicts between Kurdish separatists which is a legal party and ideologically on the same line as PKK A political party would not need a legal political branch would it