A federal judge is weighing whether to order the State Department to release internal communications between Secretary of State Mike Pompeo and two of three men designated by President Trump to steer Ukraine policy — potentially sensitive records at the heart of an ongoing House impeachment inquiry.

U.S. District Judge Christopher R. “Casey” Cooper of Washington on Tuesday heard arguments in a public-records lawsuit seeking communications by Kurt Volker, former State Department envoy to Ukraine, and the U.S. ambassador to the European Union, Gordon Sondland, with other State Department officials including Pompeo.

Volker, Sondland and Energy Secretary Rick Perry called themselves the “three amigos,” and other U.S. diplomats said the trio was tasked by the administration with pushing Trump’s policies on Ukraine, bypassing and at times running counter to traditional diplomatic channels.

A watchdog group, American Oversight, in May asked the State Department for records related to alleged efforts by Trump and his administration to pressure Ukraine to investigate a political opponent, former vice president Joe Biden, and his son Hunter, events that are the subject of a House impeachment report released Tuesday.

The Trump administration has declined to release records to the House, as part of the White House’s blanket refusal to cooperate in the impeachment probe. However, the Freedom of Information Act (FOIA) empowers judges to order the release of documents requested by members of the public, and federal lawsuits to enforce such requests can move much more quickly through the courts than battles over congressional subpoenas.

“The public should expect more disclosures, over the administration’s strong objection, for the foreseeable future,” American Oversight Executive Director Austin Evers said earlier in the litigation.

After Tuesday’s hearing, Evers added, “If I were a member of Congress and thinking about voting on articles of impeachment and whether to convict the president, I would keep in mind that the evidence is going to continue trickling out after I cast that vote, and if the trend continues, it’s not going to get better.”

The group sought records since March 2018 related to the recall of the U.S. ambassador to Ukraine, Marie Yovanovitch, and readouts from a July 25 call in which Trump asked Ukraine President Volodymyr Zelensky for “a favor” while his administration was withholding military aid.

Cooper in late October ordered the State Department to begin releasing Ukraine-related documents. American Oversight filed its lawsuit on Oct. 1. Tuesday’s hearing focused on the group’s request that the court order the department to prioritize the release of records involving Sondland and Volker, any notes of the July 25 call, and records of Pompeo’s other communications, such as a publicly reported September call with Trump’s personal attorney Rudolph W. Giuliani.

The suit has taken on added urgency as Democratic leaders have signaled they wish to conclude the House inquiry by year’s end.

American Oversight said an initial 98-page disclosure by the department on Nov. 22 documented multiple earlier communications from Giuliani through the White House to Pompeo “to facilitate a smear campaign” against Yovanovitch.

Justice Department trial attorney Joshua C. Abbuhl of the civil division’s federal programs branch argued Tuesday against a court order, saying that allowing FOIA requesters to change the department’s procedures midstream would substantially tax already stretched resources, duplicate workloads and reduce the efficiency of records searches at a time when the department faces a long backlog of requests.

“It is just very difficult to process documents that have already been” screened, Abbuhl said, adding that there is a “substantial likelihood” that Volker and Sondland’s communications could reflect internal department deliberations that would be exempt from public release.

Cooper said he would wait until Monday, when the department has said it will explain exactly how it has searched for responsive documents and over what period, but expressed skepticism at the department’s claim that it had no readouts or summaries of the July 25 call or the secretary’s other communications.

“I’ll wait to see what the department says,” Cooper said, before adding later, “It seems unlikely there would be no summaries or readouts of that call.”

American Oversight attorney Daniel A. McGrath argued that Volker and Sondland are the “key witnesses” in the impeachment inquiry and noted that Sondland himself testified that the State Department blocked him and House lawmakers from accessing his records and communications that could have bolstered his recollection.

McGrath said even if portions are redacted, the two diplomats’ communications in August and September were “likely to be of great public importance,” explaining what the White House and Trump’s personal attorney were doing and how the State Department responded.