 In 1989 , the government of the Socialist Republic of Croatia decided to tolerate political parties in response to growing demands to allow political activities outside the Communist party . The first political party founded in Croatia since the beginning of the Communist rule was the Croatian Social Liberal Party ( <unk> ) , established on 20 May 1989 , followed by the Croatian Democratic Union on 17 June 1989 . In December 1989 , <unk> <unk> became the head of the reformed Communist party . At the same time , the party cancelled political trials , released political prisoners and endorsed a multi @-@ party political system . The Civil <unk> Act was formally amended to allow political parties on 11 January 1990 , <unk> the parties that were already founded . 
