The General Assembly is the legislative body of the Imperial government. It is composed of (mostly) elected representatives from Imperium's many planets and various influential organizations.
The General Assembly is the primary instrument by which Imperial laws are devised and passed, the other method being direct Imperial Decree. Although the monarch has the authority to veto any decision made by the General Assembly, in practice this is rarely done for reasons of popularity and political expedience.
The majority of members in the General Assembly are planetary representatives. According to the Statutes, every Imperial world is entitled to representation in the General Assembly, which is most usually accomplished by means of delegating an elected representative. Colonies, defined as recently-settled planets who have not yet attained complete economic and military self-sufficiency, are not eligible and are instead represented by their parent, i.e., the planet or faction that sponsors the colonization project.
Since a number of otherwise eligible worlds fall under military administration, they are represented by military officers appointed for the job by the military governors of those planets rather than elected like civil officials. These officers also serve as a powerful representation (and lobby) of military interests in the General Assembly.
Major industrial cartels are also entitled to representation in the General Assembly, since the Imperium's economy is dominated by the massive military-industrial complex. Same is true for the scientific establishment. The methods by which representatives are chosen is an internal affair of the respective factions, and is not regulated by the government.
Because of the Imperium's size, the General Assembly is a massive and constantly-changing body of representatives. At times, reps may find themselves arriving on New Aedun to represent a lost world, conquered by the enemy during the time of their travel which may span months.
Although the Imperium's colonized and claimed worlds go well above 100 000, only around 20 thousand are actually eligible for representation in the General Assembly.
The General Assembly conducts meetings twice a month to discuss matters of importance and adopt new legislation or repeal the existing one as necessary, with the option for additional meetings being called by the Empress at her discretion.
The meetings are held in the General Assembly Hall, a vast hall in the Imperial Spire arcology on New Aedun where much of the Imperium's central government bureaucracy is housed. By far larger than the largest stadiums of Old Terra, the hall can house all attendants and their retainers with room left to spare. Holojectors project massive 3D images of every speaker, with beams of light tracing back to the actual speaker so that everyone can see the speaker as well as hear his address.
The Empress personally presides over these meetings, arbitrating heated debates and taking note of the opinions expressed before delivering her final verdict. Any Imperial law requires her assent to be passed into effect, though it is normally granted unless there exists a clear reason not to. On occasion, when the debates become unproductive or legislation ludicrous and impractical, the Empress may pass a veto. Same is true for hastily-done and incomplete legislatures, which may be vetoed on grounds of being incomplete and overly vague.
As with every Sidh government institution, only those with military background and therefore full citizenship may serve in the General Assembly. One exception is representatives of the scientific establishment, whose eligibility is determined by academic degrees held.