(ANSA-AP) - BERLIN, 04 MAR - Hungary's populist prime minister described members of a European Union political group who want his party expel led as "useful idiots," saying in an interview published Sunday they are playing into the hands of left-wing opponents. Discussion over whether Prime Minister Viktor Orban's Fidesz party should remain part of the center-right European People's Party intensified after the Hungarian government launched a public ad campaign last month opposing the positions of EU leaders on migration. Critics see anti-Semitic undertones in the billboards, posters, print and television ads that carry images of Hungarian-American billionaire George Soros and European Commission President Jean-Claude Juncker. By suggesting that Soros influences European Union policies on mass migration, some of those offended by the campaign say it evokes Nazi-era propaganda that portrayed Jews as puppet-masters and international enemies. Orban said in an interview with Germany's Welt newspaper that EU parliament members who want Fidesz kicked out of the European People's Party were "useful idiots" for the left, using an expression commonly attributed to Lenin. "While they believe they're fighting in a spiritual struggle, in fact they're serving the power interests of others - indeed, of our opponents," Orban said. Orban said Hungarians don't consider the posters anti-Semitic. "I can't do anything about the fact that George Soros is a Hungarian of Jewish origin," he added. Soros has been the target of various Hungarian government smear campaigns in the past few years. The European People's Party is the largest trans-national political group in the European Parliament. It was founded to represent Christian Democrats. Some of Fidesz's fellow members, including parties from Belgium, Portugal, the Netherlands, Sweden, Finland, Luxembourg and Greece, have fiercely criticized Hungary's campaign. The ads follow years of grumbling within the group over Orban's efforts to build an "illiberal state." (ANSA-AP).