A bill ensuring Congressional oversight on any proposed nuclear deal with Iran is headed to the President’s desk.

The bill passed through the House 400-25 after a hard-fought battle in the Senate earlier this month. It imposes a 30 day buffer preventing the President from waiving any congressional sanctions against Iran while Congress reviews the deal; additionally, if Congress disapproves of the deal, the President will be unable to waive certain congressionally-imposed sanctions.

Opponents of the bill maintained that its provisions were not strong enough to provide an adequate buffer between the Obama Administration and a nuclear Iran; its supporters, however, argued that the bill would be the best chance for the American people to weigh in on the controversial impending nuclear deal. The legislation eventually passed the Senate 98-1, with only Arkansas Senator Tom Cotton objecting.

President Obama is expected to sign the bill, giving Congress the power of initial rejection but ushering in a new round of contentious negotiations over the nuclear deal itself. The House vote came as Obama met with the leadership (though not necessarily the figureheads) of leading Persian Gulf states in a series of meetings “designed to narrow differences” over the impending nuclear deal:

The U.S. and five other international powers are trying to reach a comprehensive pact on Iran’s nuclear program by a self-imposed deadline of June 30 after agreeing on the framework of a deal in March.

Reaching a final deal with Iran would kick off the next, more partisan, round of debate in Congress over the negotiations. Republicans have accused the administration of being willing to make too many concessions to strike an agreement.

Secretary of State John Kerry “appears to be a guy who just wants a deal—whatever it takes,” Senate Foreign Relations Committee Chairman Bob Corker (R., Tenn.) said Wednesday. “The least little thing that Iran brings up, he’s so anxious to resolve it.”

Meanwhile, Russia is raising drama about the substance of the as-yet-unformed deal. Russian UN Ambassador Vitaly Chukrin has reportedly come out against allegedly agreed-to “snapback” sanctions that would fall back into place if Iran violates the terms of an eventual nuclear deal:

Churkin did not elaborate on the “no automacity” principle, but a so-called sanctions snapback mechanism whereby economic sanctions would be reimposed on Iran if it fails to comply is seen by Washington as essential for any nuclear deal with the Iran.

President Obama last month said “snapback sanctions if there’s a violation” by Iran should be part of a deal that might provide substantial relief from sanctions upfront, as Iranian leaders demand.

“Our main concern here is making sure that if Iran doesn’t abide by its agreement, that we don’t have to jump through a whole bunch of hoops in order to reinstate sanctions. That’s our main concern,” Obama said. “And I think that goal of having in reserve the possibility of putting back and applying forceful sanctions in the event of a violation, that goal can be met.”

After Secretary of State John Kerry met Tuesday with Russian President Vladimir Putin in the Black Sea resort of Sochi, the American diplomat said the two nations were “closely aligned” in their thinking on the negotiations.

Churkin’s comments, however, cast doubt on assertions by the Obama administration that Russia has agreed in principle to a snapback measure.

Congress has its backstop, but it’s not foolproof; now, we’re seeing discord between the US and Russia, and the US and the Gulf states, over mechanisms put into place to control Iran’s behavior (or lack thereof.)

This bill may not be perfect, but at least Congress is (for the most part) united in the idea that someone needs to be able to pump the brakes on what the Administration is cooking up.