Updated

The Federation of Hungarian Jewish Communities has asked Prime Minister Viktor Orban to immediately end a political ad campaign targeting Hungarian-American investor and philanthropist George Soros.

In a letter to Orban released Thursday, federation president Andras Heisler said the government's "poisonous" messages were harming the whole country.

"This campaign is not openly anti-Semitic but it is still very capable of arousing uncontrolled passions like, among others, anti-Semitism," Heisler said in the letter. "It is the historical responsibility of you, our elected leaders, to prevent hate from spreading in our nation, to not turn the Hungarian people against each other."

The government last week launched a billboard and television ad campaign seeking to discredit Soros' pro-migration views. The posters and billboards show a smiling Soros with the caption "Let's not allow Soros to have the last laugh!" and a notice claiming that 99 percent of Hungarians reject illegal migration.

Some of the posters in Budapest and other large cities in Hungary were defaced with slogans like "stinking Jew" written across the Soros image, which Heisler said confirmed the federation's fears and were reminiscent of "the dark periods of Hungarian history."

Janos Lazar, Orban's chief of staff, said Thursday that the anti-Soros campaign did not have any anti-Semitic connotations and reiterated the Hungarian government's "zero tolerance" toward anti-Semitism.

"This matter is not about George Soros' ancestry or identity but about what he does," Lazar said after a weekly Cabinet meeting. "Viktor Orban considers Soros a successful, very smart and very talented Hungarian person."

Orban last week repeated his charge that Soros is supporting a "mafia network" of civic groups and human smugglers which are bringing illegal migrants to Europe.

Soros "wants to see 1 million migrants coming from a different cultural background settled in Europe every year," Orban said. "For him migration is good business. The reason he's so angry with Hungary — and with me personally — is that we stand in the way of his grand plan and grand business project."

For his part, Soros said last month in Brussels that Orban had set up a corrupt "mafia state" in Hungary.

Hungary built fences protected by razor wire on its southern borders with Serbia and Croatia in late 2015 to stop migrants from moving through the country toward Western Europe.