The White House had said some of the stronger provisions of the original measure would have threatened delicate international talks between Iran and world powers over Tehran’s nuclear program. The negotiators have given themselves until the end of June to reach a final agreement, which members of Congress want to review.
Corker and Ben Cardin, the committee’s Republican chairman and top Democrat, have been arguing against so-called poison pill amendments. They say such amendments would alienate many Democrats who now support the measure and prompt a veto.
Senators voted down two such controversial amendments earlier this week.
There was some optimism about the bill’s long-term prospects, however. Senate aides said they expected the Republican Majority Leader, Mitch McConnell, would take steps as early as Monday to stop debate on the bill and allow a vote on a “clean” version, without amendments.
But a spokesman said late on Thursday that McConnell had not yet said whether he would do so, and that Senate leaders were still trying to find a way to have votes on amendments.
Talks between six major powers and Tehran are approaching the final stages after they hammered out a preliminary agreement on April 2, with Iran committing to reduce the number of centrifuges it operates and to other long-term nuclear limitations.