Nigeria features a bicameral legislature (the National Assembly), modelled after the political system of the United States. The National Assembly is divided into an upper house (Senate) and a lower house (House of Representatives). The Senate has 109 members, three from each state and one from the capital region of Abuja. Every four years, senators are elected in a popular vote. The House of Representatives has 360 members who are elected for a four-year term, using a simple majority (first-past-the-post) system.
The last general elections (house, senate, and presidential elections) took place in March 2015. The next general elections will be held in 2019.
Proposed laws are called bills and can be introduced either to the Senate or the House. After its introduction in the legislative process, a bill is reviewed by a relevant committee, then referred to the National Assembly. In a sequence of three readings, the bill is discussed and modifications can be made. A bill is passed by a simple majority of the upper and lower house, which vote independently from one another. In order to formally complete the legislative process, acts have to be signed by the President (Presidential Assent).