President Barack Obama, at odds with Netanyahu over the Israeli prime minister's criticism of the nuclear talks, will not meet him during his visit, saying it is a breach of protocol to receive a foreign leader before an election.
In Israel, Netanyahu has been roundly criticized even by some of his right-wing allies, mostly for appearing to put his ties to the U.S. Republican Party ahead of the close relationship Israel has always had with the United States.
In an apparent rebuttal of domestic criticism of his intention to address Congress, Netanyahu at a Monday night meeting of American Jewish leaders underlined the importance of raising questions about the Iran talks to U.S. lawmakers. In the speech, he said that the details of a possible deal with Iran were being hidden.
"Just as Iran knows what deal it has been offered, naturally, Israel also knows what are the details of the deal that is being formulated... But if somebody thinks that this is a good deal, why is it being hidden?" Netanyahu asked.
After weeks of negative commentary, officials close to the prime minister's office said last week that the format of the speech could be changed, with Netanyahu possibly speaking behind closed doors or in smaller groups of congressmen rather than in a televised address.
But Netanyahu appeared to rule out to any change of plans, saying he was determined to honor the invitation. The Israeli leader has vowed to foil what he says would be a "bad and dangerous agreement" on Iran's nuclear program.
With a month until the election, some polls suggest voters are unhappy about his appearance in Washington. A survey by Army Radio showed 47 percent thought Netanyahu should cancel the address, while 34 percent said he should go ahead with it.
Overall, however, Netanyahu's Likud party remains marginally ahead, with most polls expecting it to win 24 or 25 seats in the 120-seat parliament, just ahead of the center-left opposition.
Even if the center-left wins, most analysts expect Netanyahu will be the only one able to form a workable coalition among right-wing and religious parties, allowing him to return as prime minister for a fourth term.