New Senate legislation supported by President Joe Biden and many Democratic and Republican senators includes a significant blow to humanitarian aid for Palestinians — fulfilling a long-standing GOP goal while making it harder to address the deepening crisis in Gaza.

The bipartisan legislation unveiled Sunday night and promptly endorsed by Biden is primarily focused on military aid for Ukraine and Israel as well as overhauling U.S. immigration policy. But it includes a provision regarding funding for the chief aid organization focused on Palestinians: the United Nations Relief and Works Agency for Palestine Refugees in the Near East, or UNRWA. Breaking with the U.S.’s historic approach as UNRWA’s chief donor, the bill states no money it approves can go to UNRWA and prevents UNRWA from even receiving U.S. funding that has already been approved for the agency.

That language would prevent UNRWA from accessing any of the $10 billion the bill provides for humanitarian assistance to civilians in the relevant conflict zones including Gaza, a Senate aide told HuffPost. It would also stop the U.S. from distributing up to $300,000 previously earmarked for UNRWA, according to Seth Binder, the director of advocacy at the Middle East Democracy Center. The Senate aide noted the provision would therefore cut off American funding for UNRWA’s activities beyond the Palestinian territories, including in deeply fragile Lebanon and Jordan, which host many Palestinian refugees.

“It bars all funding in the pipeline. I don’t see any other way to read it,” said Lara Friedman, the president of the Foundation for Middle East Peace think tank.

The fate of the bill remains unclear: it would need to pass both the Senate and the House of Representatives to take effect, and House Speaker Mike Johnson (R-La.) has called it “dead on arrival” in the lower chamber. Senators are set to take their first vote on the bill on Wednesday.

The development comes after Israel last month accused 12 members of UNRWA’s 13,000-member workforce of being involved in the Oct. 7 attack by Palestinian militants that killed 1,200 Israelis and prompted Israel’s campaign in Gaza against the Palestinian group Hamas, which has since killed more than 27,000 Palestinians and displaced nearly 2 million.

UNRWA fired 10 staff members over the claim and the U.N. is investigating the allegation. The Biden administration and many top Democrats said they acknowledged the concerns about the agency, but felt it should not be impugned overall and agreed with aid experts that it is vital given its unique capacity to provide crucial forms of aid.

Democrats’ stunning turn-around on U.S.-provided funding for UNRWA is a triumph for hard-right activists and Republican lawmakers who have long sought to undermine the U.N. agency.

“This provision is in line with Republican efforts in both the House and Senate for years,” Binder told HuffPost.

“Not only did President [Donald] Trump suspend funding to UNRWA when he was in office, more recently Sen. [Jim] Risch [R-Idaho] and Rep. [Mike] McCaul [R-Texas] have put holds on that funding,” he continued, referencing the chief Republicans on the Senate and House committees on foreign affairs.

Less than a week ago, 21 Senate Democrats signed a letter asking Biden to boost humanitarian aid for Gaza, saying UNRWA “plays an indispensable role in providing lifesaving aid to people in need.”

Sen. Chris Murphy (D-Conn.), who led the letter, was deeply involved in negotiations over the text released on Sunday. Like others, including Senate Majority Leader Chuck Schumer (D-N.Y.), Murphy issued a lengthy statement praising the deal.

A spokesperson for Murphy declined to comment for this story.

The Biden administration on Monday defended the proposal. State Department spokesperson Vedant Patel said the U.S. would “redirect funding” to organizations including the World Food Program (WFP) and UNICEF.

Other U.N. organizations and independent aid groups have repeatedly challenged attacks on UNRWA and the idea that they can replace it.

“The allegations of involvement of several UNRWA staff in the heinous attacks on Israel on 7 October are horrifying … However, we must not prevent an entire organization from delivering on its mandate to serve people in desperate need,” reads a Jan. 31 statement from top U.N. officials, including the heads of UNICEF and the WFP. “Withdrawing funds from UNRWA is perilous and would result in the collapse of the humanitarian system in Gaza, with far-reaching humanitarian and human rights consequences in the occupied Palestinian territory and across the region.”

UNRWA is seen as uniquely positioned because it has operated in Palestinian regions for decades and because it provides a broad range of services, from schools to medical facilities, as well as shelters and vital supplies during periods of conflict like the current war. “Other aid agencies cannot replicate UNRWA’s central role in the humanitarian response in Gaza, and amidst the current crisis many will struggle to even maintain their current operations without UNRWA’s partnership and support,” aid groups including Save the Children, Oxfam and CARE said in a Feb. 3 joint statement, calling the agency “the backbone” of aid for Gaza.

While a number of governments joined the Biden administration in halting funding for UNRWA after Israel made its claims about an Oct. 7 link to the agency last month, some key donors like Norway have continued to funnel assistance to the organization.

“Now is exactly the wrong time to halt funding for UNRWA … We should not collectively punish millions of people for the alleged deeds of a few,” Norwegian foreign minister Espen Barth Eide argued in a Monday op-ed for The New York Times.

Amid the global debate over the U.N. agency, conditions in Gaza continue to worsen as Israel’s U.S.-backed offensive nears parts of the region where Israel previously told civilians to flee for safety. Humanitarian officials say it’s still impossible to get support to people who need it, despite growing fears of famine and worsening health conditions.

On Monday, Israeli naval fire hit an UNRWA food aid convoy traveling to southern Gaza, the agency said.