A rebellion by conservative Republicans in the House of Representatives on Wednesday delayed Congress' first vote on the Iran nuclear agreement and raised the possibility that lawmakers might never vote on a resolution disapproving of the pact.
The House was supposed to vote on a procedural motion to begin debate on Wednesday, but it was put off after some Republicans said they wanted President Barack Obama to provide more information about the deal.
As a result, the Republicans, who control Congress and for weeks had been marching in lockstep in opposition to the nuclear accord, were suddenly battling each other and possibly giving Obama the upper hand.
The dispute arose after announcements on Tuesday that deal supporters had mustered 42 votes in the Senate, more than enough to use the chamber's procedural rules to block a disapproval resolution.
Late on Wednesday, House Republican leaders developed a plan for three Iran-related votes, none of which would immediately affect the nuclear pact, even though Senate Republicans said they would stick to their original plan to vote on a resolution of disapproval.
One House vote would be on a resolution saying Obama provided too little information to Congress, a second would be to defeat a resolution of approval and a third would be a bid to eliminate Obama's ability to waive sanctions.
A law Obama signed in May gave Congress a 60-day window, ending on September 17, to vote on the nuclear agreement, between the United States, five other world powers and Tehran.
The law, the Iran Nuclear Review Act, allowed for a resolution of disapproval, which, if passed, would sink the deal, under which Iran gains relief from sanctions in return for curbing its nuclear program. A disapproval resolution would eliminate Obama's ability to waive many US sanctions on Iran.
A resolution of approval, also allowed under the law, would send a message that many members of Congress are not behind the pact if it were defeated by a large margin. But it would not affect Obama's ability to waive sanctions.
Obama would be expected to veto the proposed new sanctions measure, if it passed the House and Senate.
The rebel Republicans, led by Representative Peter Roskam, said the Obama administration had not provided all the required information about the deal. Opponents of the nuclear pact say it includes "secret side deals" about nuclear inspections that have not been fully revealed.
"He hasn't complied with the law," Roskam told reporters as he left a closed-door Republican meeting. "So (the Iran review act) isn't triggered because he's not disclosed what's required under the law."
The White House dismissed that suggestion. "If Congress does not vote, this agreement goes into effect. It's as simple as that," spokesman Eric Schultz said.
Some Republicans also said they also would sue the Obama administration over the Iran deal, arguing that the White House violated the review act by not providing the required documents.
The dispute was one of several recently between Republican leaders and the party's most conservative members. Some conservatives want to replace the Republican House Speaker, John Boehner, saying he is too willing to work with the Democrats.
Senate Republicans said the events in the House did not affect their plans. The Senate spent Wednesday debating the disapproval resolution, planning to vote this week.
"As I understand the law … we have to act before September 17, which is next week, or the deal goes forward," Senate Majority Leader Mitch McConnell told reporters.
Even if senators are unable to use the Senate's filibuster procedural rule to block the measure, deal supporters have far more than the 34 votes in the 100-member Senate needed to sustain a veto Obama has promised.
However, a disapproval resolution must be passed by both the Senate and House to get to Obama's desk.
Democrats in the House have also been steadily amassing support for the deal, with 133 members on board by late Wednesday.
To override a veto, deal opponents would need two-thirds majorities in both the Senate and House.
Some Republicans were visibly unhappy about Wednesday's developments. And the powerful House Rules Committee, controlled by Boehner, still has to approve the plan.
Representative Pete Sessions, the Republican chairman of the Rules panel, was noncommittal.
"The conference looks at things sometimes as approval or disapproval on how they want to proceed. I offer no real argument at that," Sessions said.
"We've talked it over and some people like steak and some people like seafood. I'm a steak guy."