WASHINGTON (AP) -- Conservative House Republicans have embarked on an eleventh-hour political maneuver to derail the Iranian nuclear deal, saying they can't vote on it until the president coughs up copies of side deals Tehran negotiated with atomic inspectors.

The last-ditch effort to snarl implementation of the deal was part of a political spectacle that unfolded on Wednesday in Washington over one of President Barack Obama's key foreign policy initiatives.

Inside the Capitol, congressional Republicans turned on each other angrily as they moved closer to a vote on the deal, which gives Iran billions of dollars in sanctions relief in exchange for restraints to keep it from becoming a nuclear-armed state.

Outside on the lawn, GOP presidential candidates Sen. Ted Cruz, R-Texas, and Donald Trump whipped up several thousand demonstrators with remarks harshly criticizing the deal. "Never ever, ever in my life have I seen a deal so incompetently negotiated as our deal with Iran," Trump bellowed on the hot, humid afternoon.

The maneuvering and speechifying did little to change the reality: Barring unlikely success of the House Republicans' strategy, the international accord will move ahead. Even if Congress succeeds in passing legislation aimed at undermining the deal, Obama would veto it and Democrats command enough votes to sustain the veto.

Under legislation that Obama signed into law, Congress has 60 days, or until Sept. 17, to vote to approve or disapprove of the deal, or take no action. The congressional review law required Obama to give lawmakers copies of all documents relevant to the deal.

Republican Rep. Peter Roskam of Illinois and other House Republicans are now claiming that the 60-day clock never started ticking because Obama never sent Congress the texts of two separate agreements the International Atomic Energy Agency negotiated with Tehran.

IAEA chief Yukiya Amano, who met last month with members of the Senate Foreign Relations Committee, said he has a legal obligation to keep the documents confidential.

Responding to resistance from conservative Republicans, House GOP leaders canceled the start of debate on a resolution to disapprove of the deal and hastily called a meeting to discuss how to move forward.

What emerged was a Plan B involving votes on several related measures: one to specify that the Obama administration had not properly submitted all the documents pertaining to the accord to Congress; a second, bound-to-fail vote to approve the deal; and a third to prevent Obama from lifting congressionally mandated sanctions on Iran. Debate and votes were to begin Thursday.

"It is a scandal that the administration has not disclosed this information," Roskam told reporters after emerging from the strategy meeting in the basement of the Capitol.

Roskam said he thinks it's a very bad deal and has to "use every conceivable tool" to stop it. Asked why he didn't make his argument earlier, he said: "I didn't think about it. ... As we began to move forward, it just became clearer and clear and clearer. ... This was the first opportunity."

Rep. Mike Pompeo, R-Kan., insisted that the clock had not started.

"I think the president has broken the law - that is he hasn't compiled with his obligations" under the legislation allowing Congress to review the deal. He added that if Obama lifts sanctions against Iran without explicit congressional approval, "the American people will be furious and properly so because they will have a president who is brazenly violating the law with knowledge and intent."

Democratic Rep. Louise Slaughter of New York issued a statement late Wednesday accusing the "dissident wing of the majority's party" of emerging from a neighborhood bar, Tortilla Coast, on Tuesday night with a "perversion of our legislative process."

"We are yet again thrown into chaos by a majority chasing its tail in a last-minute meeting, throwing together three bills that might as well be scribbled on the back of a cocktail napkin," she said, lamenting that the maneuver trivialized Congress. "Meanwhile, the Senate has declared that they are not changing course, and in the end, we will be left with nothing."

All the maneuvering by opponents of the deal apparently did so without an assist from the powerful pro-Israel lobby, AIPAC, which had hundreds of its members arm-twisting lawmakers on Wednesday. An official with the group said its preference was for a straight vote on the disapproval resolution - something Senate Democrats are trying to block with a filibuster.

The fate of that effort remained uncertain. In the Senate, debate did begin on the resolution, with some describing the vote, which could occur yet this week, as among the most consequential in their lifetimes.

Sen. Bob Corker, R-Tenn., the chairman of the Senate Foreign Relations Committee, urged his colleagues in the House to express their concerns about the side agreements by voting to disapprove of the deal. He said he believes that the president and the United Nations will conclude that the 60-day clock ends Sept. 17 and sanctions will start being eased.

Even if Congress received the separate agreements between Tehran and the IAEA, "I don't think that would change our view of whether allowing Iran to industrialize their nuclear program is a bad deal," said Corker, who gave a lengthy floor speech against the deal late Wednesday.

This article was written by Deb Riechmann & Erica Werner for AP on Sep. 10, 2015.