The agenda of the ongoing parliamentary session includes this motion.
Representatives of the regional parties and the IDS said that the requirement regulating the number of members was in contravention of the constitutional provision on the freedom of establishing political parties.
They also stressed that the number of members does not guarantee the quality of a party.
"The Alliance of Communists of Yugoslavia had one million members but it nevertheless disintegrated just as the state did," Damir Kajin of the IDS commented ironically.
He accused the HSP and the ruling Croatian Democratic Union of intending to create commotion on the political scene before the parliamentary elections announced for November this year.