In the early 1920s Lubomirski stayed away from political life. He decided to return to politics after the May Coup. On May 13, 1926 he talked with Pilsudski at Warsaw East Rail Station. Soon afterwards, he was among four men considered for the post of President of Poland, but refused to accept the nomination. In 1928–1935, Lubomirski was a senator of Nonpartisan Bloc for Cooperation with the Government, and a chairman of two Senate commissions – foreign affairs and military. He frequently participated in different international events, such as 1929 funeral of Marshal Ferdinand Foch.