Conservative House Republicans forced an abrupt about-face from party leaders Wednesday as a rule to debate a resolution disapproving the Iran nuclear deal was scrapped in favor of an approach involving votes on three related measures.
The first measure specifies that the Obama administration had not properly submitted the accord to Congress.
The second is a bound-to-fail vote to approve the deal, and a third would prevent Obama from lifting congressionally mandated sanctions on Iran.
Debate and votes were to begin Thursday.
"We need to pull every tool out of the toolbox to stop this bad deal," said Rep. Bill Flores, R-Texas.
The rebels were egged on by Sen. Ted Cruz, R-Texas, who has repeatedly allied himself with House conservatives to thwart the plans of GOP leaders.