A slim majority of Senate Democrats joined a letter on Wednesday that raised questions about Israeli operations inside Gaza and the provision of offensive weaponry by the United States to Israel for such operations, and sought assurances about U.S. oversight of such operations.

The letter, signed by 26 Senate Democrats, marks the largest group of senators openly voicing concern about Israel’s operations against Hamas in Gaza since Oct. 7, including from a growing number of more conventionally pro-Israel lawmakers. 

The letter asks President Joe Biden to “inform us about what specific mechanisms you are putting in place to ensure that Israeli military operations conducted inside Gaza are carried out in accordance with international humanitarian law and to ensure that any U.S.-provided equipment is used in a manner consistent with U.S. law.”

It requests for an assessment of “whether Israel’s military rules of engagement, particularly regarding mitigation of civilian casualties, align with U.S. policy and practice” and of the “viability of Israel’s military strategy in Gaza, and whether it prioritizes the release of hostages.”

The lawmakers express unqualified support for providing Israel with funding to replenish the Iron Dome missile-defense system and other defensive capabilities, but appear more concerned about offensive military aid that may be used in Gaza.

“To better understand the efficacy of U.S. funding that supports Israel’s operations inside Gaza, we respectfully ask your team to provide us with information relative to these two clear U.S. priorities: supporting an Israeli strategy that will effectively degrade and defeat the threat from Hamas and taking all possible measures to protect civilians in Gaza,” the letter continues.

The letter states that “[a]s we consider additional military assistance to Israel,” the U.S. must “insist that Israel take all necessary measures to help us facilitate such relief to the two million civilians living there, half of them children,” although it stops short of explicitly calling to condition the offensive aid on Israel taking these actions.

The lawmakers call for an extensive series of steps by Israel including “fully restoring water, electricity and communication services, expediting fuel deliveries through already well-established systems for avoiding diversion to Hamas” and opening a crossing from Israel into Gaza. They also demand that aid workers and schools, hospitals and U.N. facilities be protected.

The letter goes on to suggest a series of other concerns about Israel’s post-war strategy, including “whether there is an achievable plan for governing Gaza” after the war and “if Israel supports the conditions necessary to ultimately achieve a two-state solution.”

The senators also ask for “public assurances” that Israeli Prime Minister Benjamin Netanyahu and his coalition “will immediately stop the escalating settler violence” and from Palestinian Authority President Mahmoud Abbas that the PA will seek to stop anti-Israel violence.

The letter was signed by Sens. Chris Van Hollen (D-MD), Chris Murphy (D-CT), Brian Schatz (D-HI), Jack Reed (D-RI), Peter Welch (D-VT), Angus King (I-ME), Jeanne Shaheen (D-NH), Jeff Merkley (D-OR), Tina Smith (D-MN), Amy Klobuchar (D-MN), Raphael Warnock (D-GA), Jon Ossoff (D-GA), Ben Ray Luján (D-NM), Tammy Duckworth (D-IL), Dick Durbin (D-IL), Elizabeth Warren (D-MA), Tom Carper (D-DE), Sheldon Whitehouse (D-RI), Tammy Baldwin (D-WI), Martin Heinrich (D-NM), Mazie Hirono (D-HI), Sherrod Brown (D-OH), Ed Markey (D-MA), Laphonza Butler (D-CA), Bernie Sanders (I-VT) and Tim Kaine (D-VA).

Lawmakers such as Klobuchar and Ossoff are notable signatories, given their generally more pro-Israel postures. This is also one of Butler’s first major moves on Israel policy since assuming California’s Senate seat.

Separately, a smaller group of senators, which included Ossoff, Heinrich, Kaine, Reed and Van Hollen, as well as Sens. Mark Warner (D-VA) and John Hickenlooper (D-CO), sent another letter to Biden raising concerns about the West Bank. This letter lacks the demands for public commitments from Israel and the PA about West Bank security.

The senators said that the situation there poses threats to U.S. national security interests and civilians, arguing that “it is crucial that U.S. and Israeli policy reinforce the stability and security of the West Bank.” They described settler attacks on Palestinians as “an acute destabilizing risk that must be mitigated” to ward off greater regional conflict.

“If additional action to prevent these violent attacks is not taken, we worry that civilians and U.S national security interests will suffer grave harm,” the letter reads. “The situation is likely to exacerbate anger and grievance among the people of the West Bank and across the Arab world, inhibit efforts to cooperate with Arab states against shared threats, and undermine moderate Palestinian leaders who can offer an alternative to Hamas and make peace with Israel. Ultimately, these conditions could provoke widespread violence and a broader conflict.”

They say that the U.S. must do more diplomatically to “prevent further violence,” and request a briefing on the administration’s plan to address settler violence and forcible displacement of Palestinians.

And more than 100 House and Senate Democrats, led by Van Hollen and Durbin and Reps. Pramila Jayapal (D-WA) and Jan Schakowsky (D-IL) wrote to the president urging the administration to allow Palestinians already in the U.S. to remain in the U.S. beyond the terms of their visas and to receive work authorizations.

The programs, known as Temporary Protected Status and Deferred Enforced Departure, are used when the government assesses that it is unsafe for foreign nationals to return from the U.S. to their country of origin, due to situations like ongoing armed conflict.

“TPS or DED would enable Palestinians currently present in the U.S., including students, tourists, and workers, to be protected from a dangerous return to their homeland while affording them the ability to remain safely in the U.S. and to work legally to support themselves and their families,” the letter reads.

Also on Wednesday, the National Republican Senatorial Committee announced a new ad campaign targeting Sens. Jon Tester (D-MT), Tammy Baldwin (D-WI), Sherrod Brown (D-OH) and Bob Casey (D-PA), accusing them of “bankrolling radicals like Hezbollah and Hamas.” The ad appears to refer to the senators’ votes in favor of the Iran nuclear deal.  All four are up for re-election in 2024.

The campaign does not target Sens. Joe Manchin (D-WV), Jacky Rosen (D-NV) and Kirsten Sinema (I-AZ), who are also up for re-election in 2024. Manchin, the only one of the three in the Senate when the Obama administration signed on to the 2015 Joint Comprehensive Plan of Action with Iran, opposed the deal at the time, and Sinema voted against it in the House. Rosen was not yet in government at the time.