ap photo House Energy and Commerce Chairman Frank Pallone, D-N.J., with Rep. Cathy McMorris Rodgers, R-Wash., right, the ranking member, as they continue work on the “Build Back Better” package, cornerstone of President Joe Biden’s domestic agenda, at the Capitol in Washington, Wednesday.

WASHINGTON — A House committee dealt an ominous if tentative blow Wednesday to President Joe Biden’s huge social and environment package, derailing a money-saving plan to let Medicare negotiate the price it pays for prescription drugs.

The House Energy and Commerce Committee vote to drop the proposal from its piece of Biden’s signature 10-year, $3.5 trillion spending plan was not necessarily fatal. The separate House Ways and Means Committee kept it alive by approving nearly identical drug-pricing language.

Even so, the provision’s rejection by one committee underscores the clout that moderates looking to curb new spending — or any small group of Democrats — have as Biden and party leaders try pushing the entire package through the narrowly divided Congress.

Facing unanimous Republican opposition, Democrats will be able to lose just three House votes and none in the 50-50 Senate to send the overall measure to Biden. That’s a precarious margin for what will be an enormous bill laced with numerous politically sensitive initiatives on spending and taxes.

The committees’ votes on pharmaceutical drugs came as Biden held face-to-face meetings with two moderate Democratic senators who’ve said the overall size of the $3.5 trillion proposal is too big. The separate sessions with Sens. Kyrsten Sinema of Arizona and Joe Manchin of West Virginia underscored a stepped-up White House drive to avoid Democratic defections.

The Energy and Commerce vote on the drug-pricing language was 29-29, with three moderate Democrats joining Republicans to oppose it: Reps. Scott Peters of California, Kathleen Rice of New York and Kurt Schrader of Oregon. Tie votes in Congress are usually insufficient to keep legislative provisions alive.

Henry Connelly, a spokesman for House Speaker Nancy Pelosi, D-Calif., said lowering drug costs “will remain a cornerstone” of the party’s push for the overall bill, Biden’s top domestic priority.

Democrats are counting on the drug-pricing provisions to pay for a modest but significant part of their $3.5 trillion plan to bolster the safety net, address climate change and fund other programs. Proponents say it could save $600 billion over the coming decade.

The legislation would authorize Medicare to negotiate with pharmaceutical companies, using lower prices paid in other economically advanced countries as a yardstick. The savings produced would be used to expand Medicare coverage by adding dental, vision and hearing benefits.

The Energy and Commerce vote showed “real concerns with Speaker Pelosi’s extreme drug pricing plan,” Debra DeShong, top spokesperson for the Pharmaceutical Research and Manufacturers of America, said in a statement. The industry says the drug negotiation plan would lead to price controls that reduce investment in research into promising new cures and treatments.

Senate Budget Committee Chairman Bernie Sanders, I-Vt., a leading champion of the drug-pricing effort, said there was “no excuse” for Democrats to bow to “the extremely greedy and powerful” pharmaceutical industry. “The American people will not accept surrender,” he added.

Biden’s talks with Sinema and Manchin came as centrists’ unrest over the overall bill’s cost has prompted a delicate hunt by party leaders for a topline figure that moderate and progressive lawmakers can endorse.

“Today’s meeting was productive, and Kyrsten is continuing to work in good faith with her colleagues and President Biden as this legislation develops,” said Sinema spokesman John Labombard said. His assessment was a positive sign in a process that has seen the party’s progressives and moderates stake out conflicting demands.

Biden and Democratic leaders endorsed the $3.5 trillion figure, but in recent days have been more cautious about its ultimate size. The enormous package faces unanimous opposition from Republicans, who say its proposals are wasteful and would wound the economy.