Imperial clasification of governments

There are three basic types of governments within the Imperial borders classified by the level of their participation in the life of the empire itself.
The Allied states are those entities who, while they wish to enjoy the benefits of commerce with the empire, retain their independence. These states are served within the imperial government by the Council of Ambassadors. This body acts to communicate the collective concerns and desires of the allied states to the Emperor and to reduce friction between the allies themselves. While wielding no actual power within the empire this body does exercise a great deal of influence in the imperial court.
The Imperial Protectorates are those planets who, because of technological differentials or political instabilities are not ready for full membership in the imperial order. These worlds are overseen by imperial governors who are tasked with their development into fully contributing members of the Empire. At such time as a protectorate has become technologically advanced and politically stable enough to elect their own representatives it is advanced to the status of Member state.
The Member state is a full part of the Empire electing their own representatives to the Imperial Senate. The Senate is the Vox Popoli, the voice of the people, or so it is held by tradition. Each senator represents one political member state, whatever form the local government takes. There are some who represent only one inhabited planet in a star system while others speak for governments that span several star systems. The Emperor does not mandate what form the local government will take as long as they recognize the authority of the imperial throne and don't engage in wars using atomic weapons of mass destruction. In fact the senate membership includes representatives from each of the star spanning mega-corps. The Senate, like the Council of Ambassadors, wields little actual authority but they do propose new legislation to the Emperor for consideration. By tradition each senator may request a direct audience with the Emperor once in any given term and expect it to be granted.
The violation of the ban on nuclear weapons is the only offense on the books that can cause the empire to degrade the status of a member state to a protectorate.