WASHINGTON — With the Biden administration days away from issuing its opinion on whether Israel is violating international and U.S. law in Gaza, the lawmaker who pushed for a State Department probe of that question doubts he’ll get an honest answer.

Starting in December, Sen. Chris Van Hollen (D-Md.) rallied 19 senators to support legislation demanding assurances that all countries receiving American weaponry — including Israel — are complying with international and U.S. statutes barring violence against civilians and efforts to block humanitarian aid. In response, President Joe Biden in February issued a new policy known as NSM-20, which required federal agencies to send a report to Congress on Israel’s conduct during its Gaza operation by May 8.

The report poses a test for the White House: Will it acknowledge the alarming actions taken by its ally, strengthening calls for the U.S. to reassess its support for Israel, or will the administration risk embarrassment and outrage by misrepresenting Israeli behavior?

The administration appears to be split. The U.S. Agency for International Development and several State Department bureaus believe the administration cannot credibly say Israel is respecting either international law or the U.S. laws that require recipients of American military support to allow the free flow of U.S. humanitarian aid, according to Reuters and Devex — raising the prospect that Biden would have to withdraw military assistance. But the State Department team leading the report side-stepped the question of whether violations are occurring and instead emphasized the risks of cutting off support for Israel, per Reuters.

Meanwhile, other top State Department officials, like U.S. Ambassador to Israel Jack Lew, are internally endorsing Israel’s promises to abide by the law, despite broad skepticism of those claims from outside analysts, as HuffPost revealed in March.

Van Hollen said he’s alarmed by the disclosures about the administration’s handling of the report.

“The credibility of the U.S. government depends on it being honest and based in fact and law,” the Biden ally told HuffPost in a Thursday interview.

So far, Van Hollen said, “the reporting on the internal dynamics at the State Department clearly indicated that those who were most expert in applying the facts and the law were ignored and overlooked by those pushing a particular policy agenda.”

Together, the recent developments represent “a big warning sign, like a big flare,” with respect to the upcoming report, Van Hollen said.

The senator spoke approvingly of an alternative assessment of Israel’s actions that is already public: an independent analysis performed by an ad-hoc group of outside experts that investigated scores of examples of Israeli military actions in Gaza — incidents which, the authors said, violated international law and U.S. directives in “a clear pattern.”

Van Hollen called that assessment “a very important yardstick against which to compare what the Biden administration comes out with.” He told HuffPost he asked five of its authors to brief senators on Wednesday in a previously unreported private meeting.

“We had a total of 13 members — that’s more members than you get for a regular hearing in the United States Senate. So I think it was an expression of the depth of concern,” the senator said.

The assessment’s authors in attendance included former State Department official Josh Paul, who quit over Biden’s policy in a development first reported by HuffPost, and prominent Palestinian American attorney Noura Erakat.

The lawmakers’ openness to the assessment’s conclusions, even if they prove to run counter to the State Department’s, is extremely notable because of the pathway that Paul and his colleagues endorse. They say Israel’s military is showing “systematic disregard” for the international and U.S. norms, note “grave concerns” that the Biden administration is violating the law via prolonged backing for Israel’s offensive and urge “appropriate steps to prevent further violations” — which could range from limiting the procurement of weapons for specific Israeli units to a broad reset in U.S.-Israel cooperation.

In February, HuffPost broke the news that U.S. officials at a number of government agencies, including the State Department, the Pentagon and the National Security Council, were investigating possible Israeli war crimes like strikes on overwhelmingly civilian targets — despite public claims from Biden administration spokespeople that there was no basis for questioning Israel’s actions.

And on Friday, 88 Democratic members of the House of Representatives wrote to Biden saying that they believe Israel’s restrictions on humanitarian aid for Gaza violate U.S. law, a view shared by Van Hollen and several other senators.

Israel has been pummeling Gaza with near-total U.S. support for nearly seven months, in an offensive that’s killed close to 35,000 people per local authorities and initiated a famine there, in retaliation for an Oct. 7 attack by the Gaza-based Palestinian militant group Hamas.

Van Hollen told HuffPost observers should also look to another outside deep-dive into Israeli conduct as a point of comparison to the eventual report from the Biden administration: an April 29 brief that Amnesty International prepared in response to NSM-20. That brief focused on American-provided weapons, saying Israel has used them “in serious violation of international humanitarian and human rights law and … inconsistent with U.S. law and policy.”

“The Biden administration and the United States loses credibility when we point to reports by Amnesty or Human Rights Watch where [they] serv[e] our political interests, and sometimes ignores them when they don’t,” Van Hollen said. “In order to be credible, you need to be consistent.”

The U.S. government regularly cites those watchdogs, among others, in its own annual human rights reports and in condemning geopolitical foes like Russia and Iran.

The senator is not seeking to “prejudge” the administration’s report, he told HuffPost. He said he has been clear to “very senior” members of Biden’s national security team about what he sees as the intent of the process: “to lay out the facts and the law.

“What policies are derived from that, we can debate. … We can have an ongoing discussion and we may have differences.”

Asked about Van Hollen’s comments, a State Department spokesperson told HuffPost: “We do not want to get ahead of any official announcements or decisions.”

Action On Capitol Hill

Israeli Prime Minister Benjamin Netanyahu has resisted calls from Biden and others to temper his offensive against Hamas, instead saying the campaign must expand to Rafah, the final refuge for more than a million Palestinians displaced by the U.S.-backed campaign and the hub of aid efforts for Gaza.

Democratic lawmakers worried about the humanitarian and strategic toll of the policy have steadily become more assertive in discussing steps to rein in Israel, which is reliant on American support for its operations.

Some congressional staff have been tasked with preparing menus of options that legislators could use to pressure Netanyahu if he does go ahead with an invasion of Rafah, a senior Democratic aide told HuffPost this week.

One high-profile prospect the aide identified: forcing an up-or-down vote in the Senate on the next major proposed sale of weapons to the Israelis. The Biden administration has sought to dodge congressional scrutiny by funneling arms shipments to Israel through packages that are below the threshold for advance congressional notification, by relying on transfer authorizations that date back years and by citing emergency powers to bypass normal oversight procedures.

Though Congress last month passed a national security funding bill which authorized $15 billion in additional military aid for Israel, lawmakers and the Biden administration have significant flexibility in deciding how the country can use that money, such as what kinds of American equipment it can buy, said John Ramming Chappell, an advocacy and legal fellow at the nonprofit Center for Civilians in Conflict. His organization and 24 other humanitarian and human rights groups issued a statement after the passage of the April funding for Israel, arguing: “Congress has the responsibility to ensure that the use of appropriated funds, including for the purchase of weapons, is consistent with U.S. law and policy.”

Van Hollen told HuffPost lawmakers are engaged in “an ongoing effort …independent of the May 8 report” to refuse to send more offensive weapons to Israel until Netanyahu changes his policies to address American concerns. The senator noted that those efforts would not affect Israeli defense materials like the Iron Dome missile defense system and that the legislators involved agree on Israel’s right to self-defense.

“We’ve had months and months of President Biden making very reasonable demands, only to be mostly ignored by Netanyahu,” the senator said.

“I will say the administration has told us repeatedly that they have found NSM-20 to be a useful tool in moving the Israeli government in the right direction,” he continued, indicating that public pushback to U.S. support of the war in Gaza has not been for naught. Yet Netanyahu has yet to budge on major policies, like denying electricity to Gaza, and has not loosened the sharp limits on what aid Israel allows into the Strip. “Clearly, incremental steps are not enough when you have people literally starving to death in Gaza,” Van Hollen said.

Activists hope next week’s delivery of the Biden administration report will strengthen interest on Capitol Hill in measures to ease pain in Gaza and prevent further alleged war crimes. They are widely promoting the outside assessments related to NSM-20 and other substantial collections of data — like a tracker of incidents since October run by the American Friends Service Committee — that could have legal implications for U.S. backing for Israel.

“If the Biden administration disregards extensive evidence of the Israeli military’s violations of their assurances, it will be up to Congress to step in and make clear that unconditional arms transfers to the Netanyahu government must end,” said Chappell.

Annie Shiel, CIVIC’s advocacy director and a former State Department official, called accountability and a shift in the U.S. approach desperately overdue — and unlikely to come unilaterally from Biden.

“The Biden administration has abjectly failed to enforce U.S. law and policy, which would have required the U.S. to end its support for catastrophic harm in Gaza many months ago,” Shiel told HuffPost. “So while we sincerely hope that the May 8 report will mark a turning point in U.S. policy towards Israel, the administration’s actions to date have given us little reason to trust that this is a good-faith process.”