The American Civil Liberties Union is turning to federal court to stop the chairman of the Senate intelligence committee from repossessing the secret copies of a landmark inquiry into CIA torture.

In an emergency motion filed late on Tuesday, the ACLU asked Judge James Boasberg of the District of Columbia federal district to prevent Senator Richard Burr’s “extraordinary post-hoc request” for all copies of the full, classified 6,900-page report currently held by the Obama administration.

It is part of a persistent effort from human rights groups to keep up pressure for disclosure over one of the most infamous episodes in CIA history, despite moves by both the committee and the CIA to move on.

“The full torture report is critical for meaningful public scrutiny of the CIA’s horrific acts, as well as its lies and evasions to Congress, the courts, and the American public,” said the ACLU attorney Hina Shamsi.

The battle highlights the partisan differences over CIA torture and the investigation of it. The report was produced when the committee was led by the California Democrat Dianne Feinstein. Once Burr, a North Carolina Republican, took over the committee, he moved almost immediately to keep the full report permanently under wraps.

Should Burr take hold of the existing copies of the classified report, it would shut off legal channels for public disclosure, as Congress has immunized itself from the Freedom of Information Act (Foia). Yet the ACLU tacked on its emergency motion to its existing Foia case against the CIA, to which Burr is not a party.

The ACLU framed its argument as a move to preserve Boasberg’s authority, after contending that the CIA provided an insufficient, noncommittal response about returning its own classified copies of the report to Burr.

“Defendants’ transfer of the Final Full Report to Senator Burr would threaten the Court’s ability to order effective relief to the ACLU, and perhaps even the Court’s jurisdiction,” it argued in the motion, which was first reported by Politico.

Neither the CIA, the Obama administration nor the previous Democratic leadership of the committee has wanted to disclose the full report. Negotiations spanning most of 2014, in which the White House permitted the CIA to determine what parts of a report damaging to its reputation the public would be kept from reading, resulted in the release of a 500-page public document.

That fraction of the report, which the CIA has alleged is misleading, documented cases in which the CIA allowed detainees to freeze to death and sexually assaulted them for what it claimed was a medical procedure called “rectal rehydration”. It stated that the CIA tortured men who possessed no intelligence about al-Qaida and misled the Bush administration, Congress and the public about the value of intelligence gleaned from torture.

The Obama administration contended to Boasberg last week that the torture report is a congressional document and exempt from release under Foia. A declaration in a 21 January government filing that the full report “cannot be widely circulated or even viewed by most Executive Branch employees” has shocked human rights groups, which consider the Obama administration to be deliberately ignoring its findings.

“[N]one of the defendant agencies have freely used the Full Report; they have kept it stored in a [secure facility], with limited access,” the administration told Boasberg last week. Neither the department of State or Justice “has even opened the package with the disc containing the full Report.” Only the CIA and the Defense Department are said to have reviewed it.

Partial disclosure of the report, and the investigation leading up to it, plunged the relationship between the CIA and its Senate overseers to what observers consider an all-time low. While Burr’s attempted repossession of the report from executive branch agencies represents an olive branch to the agency, the report’s architect, Feinstein, continues a public battle with the CIA over the factual record concerning torture.

On Tuesday, Feinstein accused a CIA “accountability” panel of whitewashing agents’ breach of a firewalled shared network used by Senate investigators working on the torture report. While the panel largely absolved the CIA of wrongdoing, despite the agency inspector general’s contrary finding, Feinstein attacked the panel’s understanding of the facts, which she at times called “absurd” and “ridiculous”.

Feinstein faulted the panel chairman, Evan Bayh, her former Senate Democratic colleague, for performing what she called a misleading and “narrow” inquiry into an episode she considered a threat to legislative oversight of the CIA. At one point, Feinstein said Bayh “failed” to correct a factual error that he had “personally committed” to fixing, concerning an employee of the office of the director of national intelligence detailed to the committee, described as a committee “staffer” said to have violated security procedures.

Feinstein said the Bayh panel misrepresented a 2009 agreement between the then CIA director Leon Panetta, Feinstein and Christopher Bond, then the top Republican on the committee, governing shared access to the network. While Bayh’s panel said committee investigators were warned they were subject to monitoring, Feinstein said Bayh neglected to give that agreement its due.

“No warning inserted into a computer system by CIA personnel, and indeed no SSCI staff, could alter the agreement made between the Committee and the CIA. To argue otherwise is ridiculous,” Feinstein said in her Tuesday statement.

Neither Feinstein nor the CIA have agreed to release the terms of that agreement, which has played a critical role in their clash.

But Feinstein, the CIA, Burr and the White House have agreed in principle not to disclose the full torture report, as human rights groups desire.

On Wednesday, a coalition of those groups, led by the Constitution Project, issued an open letter to President Barack Obama urging him to reject Burr’s requested repossession.

“Accommodating Chairman Burr would deprive executive branch decisionmakers of their best chance to learn from a dark chapter of US history and would raise serious questions about your commitment to a future free from government-sanctioned torture. It would also raise serious questions about the executive branch’s commitment to abiding by the transparency obligations imposed by Congress’s Freedom of Information Act,” the coalition wrote.

In its plea for a judicial injunction over Burr’s request, the ACLU contended that the “express language of the transmittal letter ceding control of the report to the executive branch” made Foia applicable to the report, and suggested that Burr was coordinating his repossession efforts with the CIA.

“If the Court does not act now to preserve the status quo, Defendants, and in particular the CIA, are likely to attempt to evade their obligation to maintain the Final Full Report pending final adjudication of the ACLU’s FOIA claim,” it said.

The White House has declined to comment on Burr’s request.

“A key purpose of the Senate’s investigation was to ensure that the CIA doesn’t make the same mistakes again, and the Obama administration should reject cynical efforts to hide the torture report from the public and prevent the kind of transparency that holds government abuse in check,” said the ACLU’s Shamsi.