Orsat Miljenic said on Monday that he would run for president of the Social Democratic Party (SDP).
He told the press that one of his first goals was to ensure dialogue within the party and give each member the opportunity to democratically state their position.
He said the SDP needed modernisation so that it could distinguish itself from others and set high standards for itself and Croatia.
He added that one of the key goals in the period ahead was to prepare the party for local elections in May.
Miljenic, who served as minister of justice when the SDP was in power, is the fifth party member to announce that he will run for president. The others are Tonino Picula, Ranko Ostojic, Domagoj Hajdukovic and Vesna Skulic.