Under the Constitution of the Republic of Lithuania of October 1992, the unicameral Parliament of Lithuania, the Seimas, is composed of 141 MPs who are elected for a four-year term in one-candidate or multi-candidate electoral areas on the basis of universal and equal suffrage by secret ballot in direct mixed system elections.
Each qualified elector who is at least 25 years of age on the day of elections and is not connected with a foreign state by oath or pledge, and has permanently resided in Lithuania may be elected as a Seimas member.
Elected Seimas member shall only acquire all of the rights of a representative of the nation upon taking an oath in the Seimas to be loyal to the Republic of Lithuania.
The Seimas shall meet annually in two regular sessions, spring session (March 10 - June 30) and autumn session (September 10 and December 23). Extraordinary sessions shall be convened by the Speaker of the Seimas upon the proposal of at least 1/3 of all members of the Seimas, or, in cases provided for in the Constitution, by the President of the Republic.
The main powers of the Seimas shall be to:
- consider, adopt and issue laws, make amendments to the Constitution;
- approve or disapprove of the candidature of the Prime Minister nominated by the President of the Republic;
- discuss and approve the programme of the Government and supervise its policy;
- approve the State Budget, supervise its implementation and establish state taxes;
- announce presidential elections, municipal elections;
- ratify international treaties, discuss other important issues of foreign policy.
Parliament elects committees from its members to explore drafts for legislation and to clarify other issues in accordance with the Constitution. Parliamentary commissions (standing and ad hoc) are formed to carry out short-term or limited assignments.
The Seimas Statute defines the MPs' duties and rights and has the power of law. The Assembly of Elders composed of members of the Seimas Board and representatives of the Parliamentary Groups considers the work programmes of the Seimas session and approves of the draft agendas of week-or day-long sittings, co-ordinates the organisation of the work of the Seimas.