A federal judge on Friday ordered the Justice Department to give Congress the grand-jury material related to the former special counsel Robert Mueller's Russia investigation.

The decision is a massive victory for House Democrats, who have been duking it out with the Justice Department for months over obtaining a full, unredacted copy of Mueller's report.

Chief Judge Beryl Howell of the US District Court for the District of Columbia repeatedly referred to the House's impeachment inquiry into President Donald Trump as a "compelling" reason to release the material.

She also threw cold water on Trump's and his loyalists' claims that the impeachment inquiry is illegitimate and unconstitutional because the House hasn't officially voted to open a formal inquiry.

"Even in cases of presidential impeachment, a House resolution has never, in fact, been required to begin an impeachment inquiry," Howell wrote.

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A federal judge handed House Democrats a massive victory on Friday by ordering the Justice Department to turn over grand-jury material from the former special counsel Robert Mueller's Russia investigation to Congress.

Judge Beryl A. Howell, the chief judge of the US District Court for the District of Columbia, ordered the Justice Department to give the House Judiciary Committee the following:

All portions of Mueller's final report on Russia's interference in the 2016 US election that were redacted.

Any underlying transcripts or exhibits referenced in the redacted portions of the report.

The ruling also said the committee could review the material and "submit further requests articulating" the need for additional grand-jury material going forward.

Howell's decision came after months of back-and-forth between Democrats and the Justice Department over obtaining the full, unredacted report.

The report details a slew of contacts that members of President Donald Trump's campaign had with individuals associated with the Russian government during and after the 2016 election. Those interactions took place while Russia was meddling in the race to propel Trump to the Oval Office.

Mueller's report also outlined more than 10 instances in which Trump tried to obstruct justice throughout the investigation. Trump's efforts were largely unsuccessful, the report said, but only because his staff largely refused to carry out his directives.

Howell repeatedly referred to the House's impeachment inquiry as part of her rationale for ordering the release of the grand-jury material.

"The need for continued secrecy is minimal and thus easily outweighed" by the committee's "compelling need for the material," Howell wrote. "Tipping the scale even further toward disclosure is the public's interest in a diligent and thorough investigation into, and in a final determination about, potentially impeachable conduct by the President described in the Mueller Report."

The judge also threw cold water on Trump's and his loyalists' claims that the impeachment inquiry is illegitimate and unconstitutional because the House hasn't officially voted to open a formal inquiry.

"Even in cases of presidential impeachment, a House resolution has never, in fact, been required to begin an impeachment inquiry," Howell wrote.