The party of Hungarian Prime Minister Viktor Orban should leave the mainstream European center-right grouping, European Commission President Jean-Claude Juncker said, comparing Orban to French far-right leader Marine Le Pen.

The unusually sharp comments, made at a public meeting in Stuttgart, Germany, came after the Hungarian government unveiled a new poster campaign accusing Juncker and philanthropist George Soros of wanting to flood Hungary with migrants.

“Against lies there’s not much you can do,” Juncker replied, adding that Manfred Weber, the European Peoples Party’s lead candidate for the upcoming European elections, would certainly be asking himself “if I need this voice” in the EPP.

Calls have been growing for Orban’s nationalist Fidesz party to be expelled from the EPP, which groups Christian Democratic and center-right parties in the European Parliament, because of Fidesz’s stridently anti-immigration campaigns.

Fidesz’s domestic strength, however, means it has a large delegation in the European legislature, and its removal from the EPP umbrella could erode the center-right’s current dominance of the Strasbourg parliament.

Juncker, previously the longtime center-right prime minister of Luxembourg, said he had called for Fidesz’s exclusion from the EPP.

“They didn’t vote for me in the European Parliament,” he said. “The far right didn’t either. I remember Ms. Le Pen, she said ‘I’m not voting for you.’ I said: ‘I don’t want your vote.’ There are certain votes you just don’t want.”