Virginia Democrat Mark Warner became the 66th senator to publicly support the legislation. But the elevation of Sen. Benjamin L. Cardin of Maryland to ranking member on the Senate Foreign Relations Committee is expected to complicate the prospects for both panel and chamber passage of the bill (S 625) in its present form.
“He strongly believes Congress has an oversight role,” said Cardin spokeswoman Sue Walitsky. “He wants to make sure the [bill] language is consistent” with the framework agreement laid out by the Obama administration.

The bill, sponsored by committee Chairman Bob Corker, R-Tenn., and Sen. Robert Menendez, D-N.J., would forbid President Barack Obama from lifting congressionally-imposed sanctions on Iran for two months while lawmakers reveal a final nuclear agreement. Such sanctions can then only be lifted if Congress passes a joint resolution approving the deal or does nothing. The legislation would also require regular reporting to Congress that Iran has not in any way supported terrorist acts against the United States, a provision that has drawn particular fire from critics for being outside the scope of the so-called “P-5+1” nuclear negotiations.

While Cardin supports the principle of congressional review, he said on Thursday he did not want to do anything that would undermine the president’s negotiating hand in nuclear talks.