For related articles and more information, please visit OCA’s Politics and Democracy page.

 WASHINGTON – The Obama administration is rushing to reach a new deal intended to lower barriers to trade with a dozen Pacific Rim nations, including Japan and Canada, before the end of the year.

But the White House is now facing new hurdles closer to home, with nearly half of the members of the House signing letters or otherwise signaling their opposition to granting so-called fast-track authority that would make any agreement immune to a Senate filibuster and not subject to amendment. No major trade pact has been approved by Congress in recent decades without such authority.

Two new House letters with about 170 signatories in total – the latest and strongest iteration of long-simmering opposition to fast-track authority and to the trade deal more broadly – have been disclosed just a week before international negotiators are to meet in Salt Lake City for another round of talks.

“Some of us have opposed past trade deals and some have supported them, but when it comes to fast track, members of Congress from across the political spectrum are united,” said Representative Walter B. Jones Jr. of North Carolina, who circulated the Republican letter.

Without fast-track authority, however, the other countries in the negotiations might balk at American requests since they wouldn’t be sure the final deal would remain unchanged. And getting both houses of Congress to agree to the final deal might be close to impossible without the fast-track authority, which the Obama administration has requested and which is being pursued in the Senate by Max Baucus, Democrat of Montana and the chairman of the Senate Finance Committee, along with the top Republican on the committee, Orrin G. Hatch of Utah.

“This could be the end of T.P.P.,” said Lori Wallach of Public Citizen, a watchdog group that has opposed the deal, formally called the Trans-Pacific Partnership. “All these other countries are like, ‘Wait, you have no trade authority and nothing you’ve promised us means anything? Why would we give you our best deal?’ Why would you be making concessions to the emperor who has no clothes?”