The battle between Congress and the White House over Iran begins in earnest this week as the Republican-controlled Senate prepares to tackle sanctions legislation that critics say could derail nuclear negotiations.

President Barack Obama is expected to make a forceful case against the new sanctions push in his State of the Union address on the night of Jan. 21. The very next morning, Senate Foreign Relations Chairman Bob Corker, R-Tenn., will hold a hearing on "the status of talks and the role of Congress."

The face-off comes as Sens. Robert Menendez, D-N.J., and Mark Kirk, R-Ill., have been signing up lawmakers of both parties onto legislation to gradually impose sanctions if Iran does not agree to a deal by July 6. The two senators have greatly watered down their original bill from December 2013 in a bid to get a veto-proof majority of 67 members on board.

Sen. Richard Shelby, R-Ala., and his Senate Committee on Banking had been slated to hold a hearing on the Menendez-Kirk bill on Jan. 20 and vote on it Jan. 22. On Jan. 19, however, the committee delayed both actions by a week, without explanation.