Lanckorona Pact (Polish: Pakt lanckoroński) was an agreement between Polish center (Polish People's Party "Piast") and right wing parties (primarily Związek Ludowo-Narodowy and Polskie Stronnictwo Chrześcijańskiej Demokracji and several smaller parties, known as the Christian Union of National Unity alliance or Chjena) on 17 May 1923 in Warsaw. The politicians of those parties agreed to pursue stricter polonization policies and to increase the role of Catholic Church in the state. Furthermore, the program of Polonization of the Eastern Borderlands was to be initiated.