Due to the quarians' precarious existence and the need to enforce strict rationing, government is somewhat autocratic. The Migrant Fleet's operations are directed by the Admiralty, a board of five military officers who are advised by a legislative body called the Conclave.
Each vessel in the Fleet has the right to send representatives to the Conclave aboard the flagship. The number of representatives is based on crew size. Larger clans, with bigger ships and more votes, form the cores of political blocs. Opposition comes from the Outriders' Coalition, with delegates from thousands of smaller ships.
The Admiralty defers to the Conclave's decisions in most circumstances. However, if all five members agree a Conclave decision jeopardized the survival of the fleet, and cannot get the Conclave to address their concerns, they have the right to summarily overturn the legislative decision. After the Admiralty uses this extraordinary power, they must resign. If the Admiralty does not step down after using their veto the rest of the military is obliged to arrest them.
Each ship captain has authority over the vessel, but is advised by an elected civilian Council, just as the Admiralty is advised by the Conclave. This relationship may range from cooperation to polite tolerance to outright hostility, but any captain who overrules his council without good reason is relieved of command by the Admiralty.
Many quarian ships are owned by clans who pool their resources to purchase used vessels from private sellers. Large ships are prestigious for big, rich clans, but a small ship means status for a small clan with enough personal wealth to afford a private vessel. Clan vessel captains are not subject to dismissal by the Admiralty; abusive captains are a "family" problem if they do not disrupt the operations of the fleet.