WASHINGTON — The long-awaited, much-delayed day is here: Congress is finally getting its say on President Barack Obama’s nuclear deal with Iran.

The Senate Foreign Relations Committee is slated to vote April 14 on legislation from Chairman Bob Corker, R-Tenn., that would mandate congressional review of the deal. Lawmakers on the committee have filed no fewer than 52 amendments, guaranteeing a lively debate on the most controversial foreign policy issue before Congress.

Ahead of the vote, the White House has started an all-out effort to stop the bill from getting a veto-proof majority — or at least water it down enough that it doesn’t endanger the preliminary deal reached April 2. This includes amendments from the new ranking member, Ben Cardin, D-Md., to reduce the review period to 10 session days, give the president some power to start lifting sanctions in accord with the deal, and strike a certification that Iran is not engaging in terrorism against US targets.

The White House sales job has been made even harder after sharply different interpretations emerged between the US and Iranian sides regarding what exactly had been agreed to. Senate Armed Services Chairman John McCain, R-Ariz., called comments from the supreme leader, Ayatollah Ali Khamenei, a “major setback” April 9 while Sen. Mark Kirk, R-Ill., reportedly is once again pushing for a quick vote on his sanctions legislation that he’d agreed to table until the end of June.