Hungary's populist prime minister says members of a European Parliament group calling for his party's expulsion are playing into the hands of left-wing opponents.

Viktor Orban's comments to Germany's Welt newspaper Sunday come after calls within the center-right European People's Party for his Fidesz party's ouster after his government started an ad campaign seen to have anti-Semitic undertones portraying Hungarian-American billionaire George Soros and European Commission President Jean-Claude Juncker.

Orban said those calling for Fidesz's ouster "are, in Lenin's words, 'useful idiots.' 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 Hungarians don't consider the posters anti-Semitic and "I can't do anything about the fact that George Soros is a Hungarian of Jewish origin."