The ruling Fidesz party, led by Prime Minister Viktor Orban, rejects the claims of anti-Semitism and argues that the goal of the campaign is to stop Soros' migrant campaign.
Soros is an advocate of helping developing countries cope with the growing migrant crisis and has said that Europe should accept "several hundred thousand fully-screened refugees through an orderly process of vetting and resettlement."
Orban has claimed that these plans would remove control from the Hungarian government and place it in the hands of Brussels – an issue of major contention across a number of European states.
However, the note claims that the government has "willfully misrepresented" Soros' views to further its political agenda.
"As a survivor of the Holocaust who hid from the Nazis in Budapest and later was himself a refugee, Soros knows first-hand what it means to be in mortal peril," the note released on his behalf said.
"He carries the memory of the international community's rejection of Jewish refugees fleeing the Nazis. … It is from the crucible of those experiences that his empathy for refugees from war-torn Syria and elsewhere was born," it adds.
"Soros's position is entirely consistent with mainstream European values. The claim that Soros is promoting a scheme to import a million illegal immigrants into Europe is Victor Orban's fantasy."
Soros has become an increasing target of government criticism before the April 2018 election in Hungary.
Orban, once a beneficiary of Soros' university grant program, has long clashed with the billionaire investor. In April, the pair came to loggerheads amid moves by Orban to shut down the Central European University, the school founded by Soros.
Orban has also been attempting to tighten the rules which govern nongovernmental organizations, many of which have been beneficiaries of the some $400 million donated by Soros to support justice, education and human rights in Hungary.
In a weekend statement, Israel's ambassador to Hungary denounced the government's campaign, saying it "evokes sad memories but also sows hatred and fear." But hours later, Israel's foreign ministry issued a "clarification" saying that Soros was a legitimate target for criticism.
"In no way was the statement (by the ambassador) meant to delegitimize criticism of George Soros, who continuously undermines Israel's democratically elected governments," said foreign ministry spokesman Emmanuel Nahshon.
The statements were made days before Israeli Prime Minister Benjamin Netanyahu visits Hungary.
A spokesman for Soros' Open Society Foundations did not immediately respond to a request for comment, Reuters said.
— The Associated Press and Reuters contributed to this story.
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