House Democrats on Tuesday told a federal court that arguments by President Trump Donald John TrumpUS reimposes UN sanctions on Iran amid increasing tensions Jeff Flake: Republicans 'should hold the same position' on SCOTUS vacancy as 2016 Trump supporters chant 'Fill that seat' at North Carolina rally MORE’s lawyers in the Senate impeachment trial contradicted the administration’s stance in a major federal court case.

Lawyers for the House Democrats sought to use remarks by Trump lawyer Ken Starr on Monday to the Democrats' advantage in a case over access to grand jury materials from former special counsel Robert Mueller Robert (Bob) MuellerCNN's Toobin warns McCabe is in 'perilous condition' with emboldened Trump CNN anchor rips Trump over Stone while evoking Clinton-Lynch tarmac meeting The Hill's 12:30 Report: New Hampshire fallout MORE’s Russia probe.

In that case, lawmakers and the White House have argued over whether the impeachment trial qualifies as a "judicial proceeding," which would give House Democrats a stronger claim to the Mueller evidence.

ADVERTISEMENT

The Justice Department, on behalf of the Trump administration, has argued that impeachment is not a judicial proceeding. But Starr's remarks on Monday appeared at odds with this position, creating an inconsistency that House Democrats seized on in a Tuesday court filing.

“That argument has now been contradicted by the President’s counsel’s statements to the Senate, which confirm that the Senate sits as a ‘court’ rather than a ‘legislative chamber’ during an impeachment trial," the filing reads.

The development marks the latest example in which an argument advanced at the impeachment trial has risked undercutting a party's own interests in separate but related disputes.

The Democratic-led House Judiciary Committee's court filing to the U.S. Court of Appeals for the D.C. Circuit quoted Starr’s Monday remarks directly.

“The Senate is a court," Starr said Monday during the impeachment proceedings. "In fact, history teaches us that for literally decades, this body was referred to in this context as the high court of impeachment. So we are not a legislative chamber during these proceedings. We are in a tribunal. We are in court.”