The Commonwealth Congress is the chief legislative body of the Commonwealth.  It proposes, debates and passes or rejects bills and laws that affect the entirety of the Commonwealth.

The Prime Minister is an elected member of the Commonwealth Assembly.  He is selected by the President based on who could form the most effective, majority coalition.  If there is a party sitting in majority, it will most likely be the leader of that party.  The Prime Minister's duties are to direct government policy in the Commonwealth Assembly and sit with the executive body to form government strategy.

The lower level of the Congress, the Commonwealth Assembly, is made up of 501 elected members.  Three-quarters of the seats are reserved for constituency elections, while the remainder is reserved for party lists to more accurately represent the vote distribution.

The upper level of the Congress, the Commonwealth Senate, is made of 200 representatives from the 10 republics, elected entirely by party lists.   Twenty members are chosen from each republic based on votes for the parties.  No party with less than 5% of the vote is eligable for seats.