The Justice Department is feeling the heat as it continues the prosecution of former AIPAC staffers Steve Rosen and Keith Weissman.
The two officials from the American-Israeli Public Affairs Committee (AIPAC) were in 2005 indicted for passing along secret US documents to Israel in violation of the 1917 Espionage Act.
The American Jewish Committee and the Anti-Defamation League, two top Jewish lobby groups in the US, are demanding the Justice Department reconsider its case against Rosen and Weissman.
"The prosecution creates a chilling effect on legitimate speech," AJC Executive Director David Harris said in a statement last week.
"Based upon the facts that the government has divulged thus far, we hope the Department of Justice will take a close look at this case and reconsider whether it should be pursued further," he added.
In late 2004, the New York Times reported that Weissman along with fellow AIPAC employee Rosen had been questioned regarding their involvement in an espionage case.
Larry Franklin, a Middle East analyst at the Defense Intelligence Agency, was also driven into the case for allegedly passing classified information about Iran to the AIPAC members who had relayed the sensitive information to the government of Israel.
The ADL also recently released a letter it had sent last September to the deputy attorney general urging him to "review the charges, the investigation, and the prosecution of this case."
"We are mindful of and fully support our government's need to protect sensitive national security information," read the letter. "This prosecution, however, is not necessary for such protection."
The Anti-Defamation League has come under severe criticism from political analysts for serving Israel's interests rather than those of the United States.
"The ADL has virtually become 'one of the main pillars' of Israeli propaganda in the US, as the Israeli press casually describes it, engaged in surveillance, blacklisting, compilation of FBI-style files circulated to adherents for the purpose of defamation, angry public responses to criticism of Israeli actions, and so on.," renowned American author and political analyst Noam Chomsky wrote in his 1989 book Necessary Illusions.
"These efforts, buttressed by insinuations of anti-Semitism or direct accusations, are intended to deflect or undermine opposition to Israeli policies, including Israel's refusal, with US support, to move towards a general political settlement," he adds.
Meanwhile, AIPAC, considered the most powerful and connected lobbying group in Washington, has been subject to controversy in the past.
In 1992, the group's then president David Steiner was forced to resign after he was recorded boasting about his political influence in obtaining aid for Israel.
Steiner claimed to be "negotiating" with the incoming Clinton administration over who Clinton would appoint as Secretary of State and Director of the National Security Agency.
AIPAC is a "de facto agent for a foreign government", whose "success is due to its ability to reward legislators and congressional candidates who support its agenda, and to punish those who challenge it," University of Chicago professor John Mearsheimer and Stephen Walt from the Harvard University argue in their book: The Israel Lobby and U.S. Foreign Policy.
Former President Jimmy Carter has also accused AIPAC of putting enormous pressure on politicians running for office who do not share AIPAC's goals.