"The IDS is not defending Zuzul, but the right of every person to defend themselves," Kajin said at a press conference in Zagreb.
Kajin said that media reports on the foreign minister's alleged involvement in a corruption scandal were "full of contradictions".
Chief Public Prosecutor Mladen Bajic must say if any irregularities were committed in business transactions involving the MTS company owned by Zuzul's wife Tatjana, and if they were and Prime Minister Ivo Sanader refuses to relieve Zuzul of his duties, the Opposition should demand resignation of the Government, Kajin said.
Kajin was angered by accusations that the IDS had distanced itself from other Opposition parties over the Zuzul scandal because the party chairman and head of Istria County, Ivan Jakovcic, had received support from the prime minister for vital projects in Istria.
IDS member of Parliament Valter Drandic said that this was "operational cooperation" between Istria and the central government and that it did not mean political support to the ruling Croatian Democratic Union (HDZ) party or the Government.