Financier George Soros has accused the Hungarian government of using "anti-Semitic imagery" in its poster campaign against him.
Mr Soros has been vilified in a campaign costing the right-wing Fidesz government an estimated 5.7bn forints (£16.3m; $21m).
Many Hungarian Jews fear that open or concealed anti-Semitism lies behind the campaign, which the government denies.
This is the first time US-based Mr Soros, 86, has echoed that fear.
However, he also thanked those who had made it their mission to tear the posters down.
The most recent series of posters - many of which have had anti-Semitic graffiti scrawled on them - show a grinning Mr Soros beside the words, "Don't let Soros have the last laugh".
The slogan is a reference to the government's claim the philanthropist is working to settle a million migrants in the EU.
In a statement, Hungarian-born Mr Soros said: "I am distressed by the current Hungarian regime's use of anti-Semitic imagery as part of its deliberate disinformation campaign.
"Equally, I am heartened that together with countless fellow citizens the leadership of the Hungarian Jewish community has spoken out against the campaign."
Mr Soros has spent $12bn, mostly through his Open Society Foundations, on civil initiatives to reduce poverty and increase transparency, and on scholarships and universities around the world, especially in Eastern Europe and the former Soviet Union, since the 1980s.
It has seen him come up against Hungarian Prime Minister Viktor Orban, who has declared war on liberalism.
Most recently, the university Mr Soros founded has come under attack after MPs passed a bill which could force it out of Hungary.
The posters have also drawn anger from outside the country.
Guy Verhofstadt, the chief Brexit negotiator at the European Parliament and leader of the Parliament's liberals, wrote on Facebook: "The Hungarian regime's xenophobia and demonization of refugees are anti-European. The claim that Soros is promoting a scheme to import a million illegal immigrants into Europe is Victor Orban's fantasy. Darkness falls in Hungary. We cannot let this happen."