The elections to the Sejm took place on January 26, 1919.[1] At that time, Poland did not have fixed boundaries, and was involved in territorial conflicts and disputes.[1] On the territories under the nascent Polish state's control, in the lands of former Congress Kingdom and Podlasie region, and western Lesser Poland, 42 electoral districts returned 302 deputies.[2] In addition, 20 Polish deputies to the German Parliament, 26 Polish deputies to the Austro-Hungarian Parliament, and selected candidates from the Cieszyn region (where elections were disrupted due to hostilities) were added to the Sejm.[3] In the coming months, as the Polish control grew over some disputed territories, more elections were held: on April 25, 1919, in Greater Poland and on June 15, 1919 in the Białystok and Podlasie regions.[3] Some deputies who were provisional representatives yielded their seats to the newly elected ones.[3] On March 24, 1922, the Sejm was joined by 20 deputies from the Republic of Central Lithuania (the dissolved Sejm of Central Lithuania).[3] The Sejm thus had a changing number of deputies, starting at 348 and ending its term with 432 members.[3] About 5 million votes were cast in the election.[4]
Due to the changing number of deputies, and the ongoing fragmentation and merger of various parties, there is a number of different composition listings for the Legislative Sejm.[a]
The composition of the Legislative Sejm was as follows:[4][7]
a.^ Neither Nohlen and Stöver nor Jędruch did retain original for Polish parties and groups; they used their own translations. As such, identification with a particular entity was not always possible.