Sen. Patrick Leahy (D-Vt.) called Benjamin Netanyahu’s planned speech to Congress “tawdry” and said he would not attend, the most senior Democrat in the Senate to say he will stay away.

“The unfortunate way that House leaders have unilaterally arranged this, and then heavily politicized it, has demolished the potential constructive value of this Joint Meeting,” Leahy, the top Democrat on the Judiciary Committee and a senior member of the Appropriations Committee, said Tuesday on his website.

Rep. John Boehner (R-Ohio), the Speaker of the U.S. House of Representatives, on Jan. 21 invited the Israeli prime minister to address Congress, in part to rebut President Barack Obama’s claims that nuclear talks between Iran and the major powers were constructive.

“They have orchestrated a tawdry and high-handed stunt that has embarrassed not only Israel but the Congress itself,” Leahy said.

So far, including Leahy, three Democratic senators have said they will not attend the speech to a joint session of Congress on March 3. Both of the others, Sen. Bernie Sanders (I-Vt.), who caucuses with the Democrats, and Sen. Brian Schatz (D-Hawaii) are Jewish.

Schatz was not attending “because it does more harm than good to the bipartisan U.S.-Israel alliance,” according to a CNN reporter posting on Twitter.

Netanyahu, meanwhile, persisted in insisting he would come. “I am going to the United States not because I seek a confrontation with the President, but because I must fulfill my obligation to speak up on a matter that affects the very survival of my country,” he said in a three-minute televised address to Israelis Tuesday evening.

J Street, a liberal Jewish Middle East policy group, meantime wrote to Congress members urging them to prevail upon Boehner to postpone the speech, in part because its March 3 date is just two weeks before Israeli elections. It noted that other Jewish leaders have objected to the timing, and also that Netanyahu had in a previous election used a speech to Congress in a campaign ad.

The Zionist Organization of America, meanwhile, in a statement urged Jewish leaders to back away from calling for a postponement, saying such pleadings echoed American Jewish groups in the 1930s and 1940s who allegedly tried to silence Jewish activists who warned about the perils facing Jews in Nazi-occupied Europe.

The Washington Post reported Tuesday that two liberal grassroots groups, including MoveOn, are considering actions that would pressure Democrats to stay away from the speech.