WASHINGTON, D.C. – “The more I hear from the [Obama] Administration and its quotes, the more it sounds like talking points that come straight out of Tehran,” exclaimed the top Democrat on the Senate Foreign Relations Committee, Robert Menendez (D-NJ), accosting Deputy Secretary of State Anthony Blinken and Undersecretary of Treasury for Terrorism and Financial Intelligence David S. Cohen at a hearing focused on the Iran negotiations on Wednesday. The outburst — Menendez’s response to the Obama Administration’s threat to veto a sanctions bill being proposed by Menendez and Senator Mark Kirk (R-IL) — prompted audible gasps and side glances from audience members at the hearing.

Both Cohen and Blinken argued that any new sanctions imposed by Congress would be perceived as a violation of U.S. commitments pursuant to the Joint Plan of Action by the international community and would undercut the U.S.’s ability to exact strict limits to Iran’s nuclear program. Menendez, who has reportedly been unable to recruit significant Democratic support for his legislation over the opposition of the White House and a wide range of current and former officials including Hillary Clinton and European foreign ministers involved in the nuclear talks, laid into the Administration for its opposition. Iran’s parliament would likely require approval of a deal, Menendez claimed, yet the White House was not letting Congress play a role in the process. “Tehran [treats] its parliament better than the Administration is willing to its Congress,” said Menendez. Blinken and Cohen, however, reminded the Senator that Congress would need to take its own vote to lift the sanctions as part of any nuclear deal, just as Iran’s Parliament will likely be required to formally ratify the Additional Protocol—a regime of enhanced nuclear inspections and monitoring mechanisms—under a final deal.

Other Senators took a different tact than Sen. Menendez, arguing that the White House could not sign off on a nuclear agreement without ongoing Congressional input and Congressional assent to a comprehensive nuclear deal. Blinken and Cohen argued, however, that U.S. interests were best served by suspending – rather than lifting – sanctions at the outset in order to establish a record of Iran’s compliance with the nuclear deal. As Cohen said, suspension of sanctions would be “phased and tied to specific milestones that the Iranians would have to meet.” Thus, while Congress would play a critical role in implementing a nuclear deal, a Congressional vote would not be needed until the Administration was prepared to lift the sanctions permanently.

Senator Rand Paul argued that the White House should work with the Congress so that mutual interests are served: Congress plays a role in the negotiations, while the Administration leverages permanent sanctions relief to win Iran’s nuclear concessions. As Paul said – noting the fact that the Administration was limited to suspending sanctions for 120-180 days – “I don’t know what [120] days really gives you [in the negotiations]. Iran hasn’t done years of negotiating to get 120 days of sanctions relief. They want permanent relief. That is the carrot we’re dangling.” Sen. Paul urged the Administration to work with Congress on a bill that was mutually satisfactory.

Meanwhile, next door at the Senate Armed Forces Committee hearing, the issue of a potential Congressional vote was raised with two veteran national-security experts who testified at a separate hearing– Zbigniew Brzezinski, the former U.S. National Security Advisory during the Carter Administration, and Brent Scowcroft, a two-time former U.S. National Security Advisor.

Brzezinski argued that the level of Congressional involvement in the nuclear talks should “depend on the other partners (the P5+1) in the negotiations.” Brzezinski stated, “[The U.S.] is not the only ones negotiating,” and thus an up-or-down vote on a nuclear deal should not lie solely in the hands of Congress.When pressed by Sen. Graham on whether Congress should look at any nuclear deal after it has been agreed to, Brzezinski responded: “I think you will do it anyway, won’t you?”

But if Congress were to reject a deal that the P5+1 and Iran agreed to, Brzezinski noted, it would jeopardize the entire international consensus regarding Iran’s nuclear program and would antagonize key partners of the U.S. who might not otherwise be willing to endure the substantial economic burdens of the U.S. sanctions on Iran. For this reason, Congress’ role needed to be more limited, said Brzezinski.

With both sides of the Congressional aisle wanting Congress to have more influence in the negotiations, legislation pushing for more oversight might be in the offing. But whatever Congress’s role turns out to be regarding a nuclear deal, Scrowcroft argued that it was important to recognize that the U.S. is dealing with a completely different Iran than in years past. As Scowcroft noted, “We should see negotiations out and not take steps which could destroy [them].”