At the end of the 1980s, the Socialist Bloc of Eastern Europe started to disintegrate, and the party faced one of the biggest crises in its history. With many members leaving, the party called a thirteenth congress for May 1990, in which a huge ideological battle occurred. The majority of the more than 2000 delegates decided to continue the party's "revolutionary way to Socialism" — i. e., to retain its Leninist ideology. By so doing, it clashed with what many other communist parties around the world were doing. The congress asserted that socialism in the Soviet Union had failed, but a unique historical experience, several social changes, and several achievements by the labour movement had been influenced by the Socialist Bloc. Álvaro Cunhal was re-elected secretary-general, but Carlos Carvalhas was elected assistant secretary-general.