Hungarian Socialist party Chairman Attila Mesterhazy resigned on Thursday after the party suffered crushing defeats in national and European Parliament elections, news agency MTI reported.
MTI cited a statement by Mesterhazy as saying he would also relinquish his position as parliamentary leader of the party, Reuters reported.
The Socialists came third in Sunday's European election, overtaken by far-right Jobbik and just edging ahead of former Socialist Prime Minister Ferenc Gyurcsany's Democratic Coalition.