The Justice Department sided with President Donald Trump on Tuesday in his fight to stop a congressional subpoena for eight years of his financial records, telling a federal appeals court that lawmakers had not done enough to say why they need the information.

“The House’s lack of responsibility is sufficient reason for this Court to declare this subpoena invalid,” the DOJ wrote in a brief in the U.S. Court of Appeals for the D.C. Circuit.

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The Justice Department said that “at an absolute minimum,” the appeals court should require the House Oversight and Reform Committee to provide more clarity about the legislative purpose for seeking Trump’s records from his accounting firm, Mazars USA.

The department weighed in after the three-judge panel that will decide the issue asked for DOJ’s views in the case, Trump v. Mazars — one of two filed by Trump as part of his fight-all-the-subpoenas approach to congressional oversight this year. House lawyers now have a chance to respond by Aug. 20.

The Justice Department wrote that judicial review of the purpose for congressional subpoenas is “more complex and more sensitive when Congress targets the President.” That’s particularly true, the department wrote, because of “significant constitutional constraints on Congress’s authority to regulate the President.”

The House, on top of telling the court last month that it has oversight interests and had repeatedly expressed a legislative reason for needing to see the records in committee memos, passed a resolution to authorize the subpoena.

The DOJ said that resolution only “underscores the need for this Court to require the House itself to provide a clear explanation of the purpose of this specific subpoena.”

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If the subpoena isn’t rejected here, the department wrote, “the resolution’s carte-blanche approval of all future subpoenas directed toward the President would vastly increase the risk that this Court will be confronted with difficult litigation about the validity of sweeping subpoenas purportedly justified by vague incantations of hypothetical legislative purposes.”

House General Counsel Doug Letter argued last month that a lower court had correctly decided that the committee’s legislative purpose was valid on its face.

That included “investigating issues of national importance” such as ethics in the executive branch, the accuracy of Trump’s financial disclosures and the ongoing management of the lease of the Old Post Office Building as the site of the Trump International Hotel, the House argued in the case.

The committee also wants to dig into possible violations of the emoluments clause of the Constitution by accepting payments from foreign governments, the House contended.

The president’s lawyers say the committee overstepped its authority to ask for the Mazars records, mainly because the committee does not have a legitimate legislative purpose for the request.