By Richard Cowan
WASHINGTON (Reuters) - Senator Robert Menendez, who is widely expected to oppose a proposed nuclear deal with Iran, is set on Tuesday to formally announce his position on the pact.
Congress is poised to vote in September on the U.S.-led international agreement. As proposed by President Barack Obama and other world powers, the deal aims to curb Iran's nuclear program in exchange for lifting economic sanctions on the country.
To prevent it from being killed by Republican opponents in the U.S. Congress, Obama needs to lock up support from his fellow Democrats, but he has a long way to go.
Menendez worked on legislation setting the congressional review process for the deal and he has made sharp comments, leading some to speculate that he would end up opposing it. Aides to the senator would not give any hint of his decision, however.
Earlier this month, Obama suffered a setback when Senator Chuck Schumer, the chamber's third-ranking Democrat, announced his opposition. At least 18 Democrats have said they will back the deal, far short of the 34 needed to keep it alive by sustaining a likely Obama veto of any disapproval legislation.
One Senate Democratic aide said on Monday that as many as 20 Democrats in the chamber now favor of the deal. Senate Democratic Leader Harry Reid was expected to declare his position in early September.
When the Senate convened in January under Republican control, Menendez had to relinquish his Foreign Relations Committee chairmanship. His fortunes slipped further in April, when a grand jury indicted him on corruption charges and he stepped down from his post as the senior Democrat on the panel.
Menendez denies any wrongdoing and is fighting the criminal charges.
Months before the Iran negotiations wrapped up, Menendez spoke to the American Israel Public Affairs Committee, which is furiously working to kill the deal, stressing his close ties to Israel while questioning Iran's intentions.
"You can be certain the mullahs (Iran's leaders) are not going to call us in Washington when they decide to breach the agreement. They're going to sneak out, covertly, gradually over time, when they think we're not looking," he said.
Besides the United States and Iran, the deal includes Russia, China, the United Kingdom, France, Germany and the European Union.
Menendez will announce his position during a speech on Tuesday at Seton Hall University in New Jersey.
(Editing by Kevin Drawbaugh and Christian Plumb)