“I hope we can defeat it, but the procedure is obviously stacked in the president’s favor,” Senate Majority Leader Mitch McConnell said, Yahoo News reported.
He added, “He (Obama) can win by getting one-third plus one of either house, so he has still got a great likelihood of success.”
Iran and the Group 5+1 (Russia, China, the US, Britain, France and Germany) finalized the text of lasting deal on Tehran’s nuclear program on July 14.
While the United Nations Security Council has adopted a resolution to endorse the deal, the text of the document needs to be ratified by both Iran's Parliament and the US Congress.
US President Barack Obama has promised a swift veto in the event of a Congressional rejection of the agreement in September. Lawmakers would then have to find enough votes to override the president.