Continual fragmentation of parties and a succession of minority governments led conservative forces to merge the Liberal Party (Jiyūtō) with the Japan Democratic Party (Nihon Minshutō), an offshoot of the earlier Democratic Party, to form the Liberal Democratic Party (Jiyū-Minshutō; LDP) in November 1955, called 1955 System.
In October 1955, socialist groups reunited under the Japan Socialist Party, which emerged as the second most powerful political force.