The Centrolew was a coalition of several Polish political parties (PSL Wyzwolenie, PSL Piast, Narodowa Partia Robotnicza, PPS, Stronnictwo Chłopskie and Polskie Stronnictwo Chrześcijańskiej Demokracji) after the 1928 Sejm elections

Polish legislative election, 1928

The Polish legislative election, 1928 lasted from 4 to 11 March and was the third election in the Second Polish Republic. Bezpartyjny Blok Współpracy z Rządem ) - a coalition of the Sanacja faction - won the highest number of seats The Polish legislative election, 1928 lasted from 4 to 11 March and...

. The coaltion was directed against Józef Piłsudski and the Sanation

Sanacja

Sanation was a Polish political movement that came to power after Józef Piłsudski's May 1926 Coup d'État. Sanation took its name from his watchword—the moral "sanation" of the Polish body politic...

 government.

To counter the Centrolew, prior to the 1930 Sejm elections

Polish legislative election, 1930

Polish legislative election, 1930, also known as the Brest elections , were the elections to the Sejm on 16 November 1930. The pro-Sanacja Bezpartyjny Blok Współpracy z Rządem party took 56% of the votes...

, Centrolew politicians were subjected to repressions (most famously, imprisonment in the Brest Fortress

Brest Fortress

Brest Fortress , formerly known as Brest-Litovsk Fortress , is a 19th century Russian fortress in Brest, Belarus. It is one of the most important Soviet World War II war monuments commemorating the Soviet resistance against the German invasion on June 22, 1941...

, and the subsequent Brest trials

Brest trials

The Brest trials were among the most famous trials conducted under the Second Polish Republic. Lasting from October 26, 1931 to January 13, 1932, they were held at the Warsaw Regional Court where leaders of the Centrolew, a "Center-Left" anti-Sanation-government political-opposition movement,...

). The Centrolew was defeated in the elections and broke up as a coalition.