WASHINGTON – The Justice Department told a federal judge that a House committee investigating President Donald Trump is not entitled to grand jury evidence from special counsel Robert Mueller's investigation, saying it has failed to explain which specific testimony it needs access to or how it would help its investigation into potential obstruction by the president.

"There is this generalized notion that this is an important matter because of impeachment and, therefore, (the committee) should have access to everything," Elizabeth Shapiro, an attorney in the Justice Department's Civil Division, said during a two-hour hearing in federal court Tuesday. "It also needs to be particularized, and they shouldn't get a pass on that because of impeachment."

U.S. District Court Judge Beryl Howell heard arguments on whether the House Judiciary Committee should receive the underlying grand jury evidence behind Mueller’s report on Russian interference in the 2016 presidential election.

The panel subpoenaed the evidence as part of the wide-ranging impeachment investigation of Trump, who calls the inquiry a partisan witch hunt. The Judiciary Committee is focusing on potential obstruction of justice, as described in 10 episodes in the Mueller report. But Attorney General William Barr redacted grand jury evidence from the report and argued against disclosing it under the subpoena.

Shapiro said there first needs to be a "degree of formality" in the form of a full House vote on an impeachment inquiry before treading into dangerous territory of "penetrating grand jury evidence." House Democrats have argued that a full House vote isn't necessary to move forward with an impeachment inquiry.

"I think we can look at history," Shapiro said, citing the impeachment investigation of Richard Nixon. "Grand jury information only went to the House after there is a formal vote."

A ruling by Howell, chief judge for the D.C. district who oversees the grand jury, could resolve a key dispute about the status of the House's investigation of Trump.

Six committees have been conducting investigations of Trump since Democrats regained control of the chamber in January. House Speaker Nancy Pelosi, D-Calif., announced Sept. 24 that all of the inquiries now fall under the umbrella of a formal impeachment investigation and that no floor vote is necessary. But Republicans have argued that only the full House can authorize an impeachment inquiry.

Mueller’s 22-month investigation found no conspiracy between Trump’s campaign and Russia, despite that country's sweeping and systematic effort to influence the 2016 election. But the report released in April outlined potential obstruction when Trump tried to thwart the special counsel inquiry and have Mueller removed. Mueller made no decision about whether to charge Trump with obstruction because Justice Department policy forbids charging a president while in office.

The Judiciary Committee subpoenaed grand jury evidence to explore Trump’s knowledge of Russian efforts to interfere in the election, the president’s knowledge of potential criminal acts by his campaign or administration, and actions taken by former White House counsel Don McGahn. The Mueller report described episodes when Trump directed McGahn to remove the special counsel, which McGahn ignored.

But Douglas Letter, counsel for the House, said the committee has "gotten nowhere near" what it thought it will be able to get as part of its investigation. He said the committee has received a "very limited" number of FD-302 forms, which are FBI documents summarizing interviews with witnesses. He said the committee has yet to receive 302 forms involving McGahn, whom the committee views as a key witness.

"The very heart of what we need to look into ... we're getting almost nothing," Letter said.

"We need to find out, was he engaging in helping to fix the election? ... Did he have a motive, and did he obstruct justice?" Letter argued. "The only way that we were going to be able to do that is see what was in those redactions."

The Justice Department has argued in legal filings that a “minuscule” 0.1% of the Mueller report dealing with potential obstruction of justice was redacted. And the department said releasing the evidence could hurt pending cases that grew out of the Mueller investigation.

Also at the heart of the debate is what exactly the impeachment inquiry covers.

Shapiro said that the findings of the Mueller report "is not currently the basis" of the impeachment investigation and that it is narrowly focused on allegations that Trump pressured the president of Ukraine to investigate a potential presidential rival.

But Letter said the impeachment investigation's scope is wider than that and covers potential obstruction of justice by the president.

"We don't just have an impeachment investigation that's focusing on Ukraine" even though "the media is focusing on that," Letter said.

In legal filings, the House Judiciary included a 1974 letter from the Watergate era as an exhibit. Rep. Peter Rodino, D-N.Y., who was then head of the Judiciary Committee, wrote to U.S. District Court Judge John Sirica asking for grand jury materials in the investigation of President Richard Nixon. Rodino cited a House vote of 410-4 to authorize an impeachment investigation.

The top Republican on the committee, Rep. Doug Collins of Georgia, also filed an argument in the case urging the judge to reject the request. Collins said that Congress sometimes deserves access to grand jury evidence but that the Judiciary Committee shouldn't gain access yet, for lack of a full House vote.

“The problem for the committee, however, is the House has not authorized it to conduct a formal impeachment proceeding,” Collins said in the filing. “Without an explicit delegation of authority from the House, the committee’s investigation is regular legislative oversight and does not fall within” rules governing access to grand jury evidence.

Separately, the committee filed another federal lawsuit to force McGahn to testify. The White House has opposed the move under a claim of absolute immunity, which Democrats contend doesn’t exist.

More on congressional investigations of President Donald Trump:

Nancy Pelosi announces formal impeachment inquiry into Donald Trump over Ukraine scandal

'We're fighting all the subpoenas.' Congress and Trump prepare to battle over wide-ranging probes

'Slow-motion constitutional car crash': Trump, Congress battle over investigations with no end in sight