Sen. Bernie Sanders (I-Vt.) took another step in his effort to place conditions on future aid to Israel on Thursday, by introducing legislation that could force the State Department to release a report detailing potential human rights violations during the ongoing war on Gaza.

The resolution was made pursuant to Section 502B(c) of the Foreign Assistance Act, meaning that it is privileged and that Sanders can force a vote on it 10 days after it is introduced in committee.

Sanders has been one of the most vocal supporters of conditioning aid to Israel. In November, he wrote in a New York Times op-ed that “[t]he blank check approach must end,” and that the United States “must make clear that while we are friends of Israel, there are conditions to that friendship and that we cannot be complicit in actions that violate international law and our own sense of decency.”

He later voted against President Joe Biden’s $110 billion emergency supplemental because, he said, it included $10.1 billion with “no strings attached” for the Netanyahu government’s “inhumane” war against Gaza. He and a number of Senate Democrats also sent an open letter to Biden last week calling for stronger oversight of the U.S. weapons being sent to Israel.

Sanders’s latest effort, if approved by the Senate, would force the State Department to release a report containing “all available credible information concerning alleged violations of internationally recognized human rights by the Government of Israel” and the steps Washington has taken to “promote respect for and observance of human rights as part of the Government of Israel’s activities.” Sanders is also asking for evidence that no Israeli security forces that have received American assistance are guilty of committing any human rights violations. According to Section 502B, if the State Department does not produce the report within 30 days of passage, the target country does not receive any security assistance.

A report from Amnesty International published earlier this month found that U.S-made munitions were used in two unlawful Israeli strikes in Gaza in October.

“The organization found distinctive fragments of the munition in the rubble of destroyed homes in central Gaza following two strikes that killed a total of 43 civilians – 19 children, 14 women and 10 men,” reads the report. “In both cases, survivors told Amnesty International there had been no warning of an imminent strike.”

This week, the Biden administration did offer some pushback on weapons sales to Israel, when it delayed the 20,000 assault rifles over fears of settler violence in the West Bank. Reports say that the administration is seeking stronger assurances from the Israeli government that the weapons will not be given to settlers.

Section 502B(c) is a rarely used national security tool. It has not been successfully employed to get a report from the State Department since 1976, and it was most recently tried earlier this year when Sens. Chris Murphy (D-Conn.) and Mike Lee (R-Utah) introduced a resolution that would have investigated Saudi Arabia’s human rights violations. The resolution has not yet been brought to a vote, though Murphy and Lee could in theory still force one until the end of this congressional session.

“Senator Sanders’ resolution marks a historic invocation of Section 502B, a potent but underused human rights oversight tool,” John Ramming Chappell, a fellow at the Center for Civilians in Conflict, said in a statement. “The resolution provides a pathway to meaningful scrutiny of U.S. security assistance to Israel as U.S. weapons contribute to devastating harm to civilians in Gaza.”

The Biden administration has maintained that it is not tracking Israel’s compliance with the laws of war in real time, but, according to a Politico report on Thursday evening, the U.S. has already begun to collect data and intelligence that could help make these determinations.

“State Department officials are also collecting reports of potential Israeli violations through a system unveiled in August called the Civilian Harm Incident Response Guidance, or CHIRG, according to Josh Paul, who quit the department over concerns about its approach to the war,” reports Politico. “Paul said some officials within the department’s Bureau of Political-Military Affairs have asked State’s legal wing to ‘provide information about their potential international law exposure as a result of approving these sales.’”

A senior American official told the Washington Post last week that the U.S. government was unable to make these judgements as events happen because they lacked access to the necessary Israeli intelligence. But Brian Finucane, a former state department lawyer, told Politico that this is not the case. “It's really disingenuous for people in the government to claim that it's too hard or we can't do this in real time,” Finucane, now a senior adviser at the International Crisis Group, said. “It's simply a choice. They choose not to do this.”

If the Senate were to approve Sanders’ resolution — which seems unlikely given the widespread support for Israel in Congress — and the State Department were to produce a report, Congress would then have the opportunity to adopt a resolution that would restrict or end security assistance to Israel. Such legislation would have to go through both chambers of Congress and be signed by the president.