This stage of the PREC lasted until the 25 November 1975 pro-communist coup, which was followed by a successful counter-coup by moderates, and was marked by constant friction between liberal-democratic forces and leftist-communist political parties. Portugal's first free election was held on 25 April 1975 to write a new constitution replacing the Constitution of 1933, which prevailed during the Estado Novo era. Another election was held in 1976 and the first constitutional government, led by centre-left socialist Mário Soares, took office.