The House Ways and Means Committee filed a lawsuit Tuesday to quickly enforce its subpoena for President Donald Trump’s tax returns, calling the government’s refusal to turn over the records “an extraordinary attack” on congressional oversight.

The lawsuit in federal district court in Washington is the first legal action from House Democrats to enforce a subpoena among the numerous investigations into the Trump administration launched since taking control of the chamber in January.

[Trump’s tax return battle will be fought in court, Mnuchin says]

The government has declined to comply with Chairman Richard E. Neal’s subpoena that seeks six years of the president’s personal tax returns and six years of returns from eight of the companies that he owns.

Democrats have leaned on a 1976 statute enacted in the wake of the Watergate revelations that requires the Treasury Department to provide “any” tax return requested by the Ways and Means chairman in writing, and in the lawsuit they stress congressional oversight power.

“In refusing to comply with the statute, Defendants have mounted an extraordinary attack on the authority of Congress to obtain information needed to conduct oversight of Treasury, the IRS, and the tax laws on behalf of the American people who participate in the Nation’s voluntary tax system,” the lawsuit states.

[Mnuchin refuses to comply with subpoenas for Trump tax returns]

The Justice Department released an opinion last month that backed up the Treasury Department’s decision not to comply with the subpoena, concluding that the “true aim” was to make the documents public and that “is not a legitimate legislative purpose.”

The lawsuit notes that nothing in the law requires the committee to explain its reasons for seeking tax return information, “but the Committee’s need for the materials requested here is evident.” It points to committee investigations into IRS administration of tax laws and policies relating to presidential tax returns and Trump’s compliance, including the tax agency’s annual audit of returns of sitting presidents.

And House Democrats seek to use Trump’s own criticisms of the IRS against him to point out why such a review would be warranted, arguing that without the information the committee can’t exercise its legislative judgment on whether the tax code needs to change.

“Indeed, President Trump himself has repeatedly questioned the integrity of the process by which the IRS audits his tax returns, complaining that his returns are under ‘continuous audit’ and that the IRS’s policy of annually auditing Presidential returns is ‘extremely unfair,’” the lawsuit states. “The President has also publicly theorized that the IRS audits him because of his assertedly strong Christian faith.”

Democrats also point in the lawsuit to legislative proposals related to presidential tax returns and a number of Trump’s public statements about the returns, including an April 2019 comment that he “would love to give [his returns to Congress], but I’m not going to do it while I’m under audit. It’s very simple.”

The lawsuit argues that time is of the essence. “This injury is irreparable because the House is not a continuing body, so the Committee’s oversight investigation will necessarily end on January 3, 2021,” the committee wrote in the complaint.

“If this Court does not redress Defendants’ noncompliance quickly, the Committee will be unable to fulfill its essential role of overseeing the Executive Branch or to carry out its constitutional obligation to legislate on issues of paramount national importance before the current Congress ends,” the lawsuit states.

Rep. Kevin Brady of Texas, the committee’s top Republican, called the lawsuit  “partisan” and “flawed,” and added that the committee never voted to authorize it. Brady said he would introduce a resolution on the issue.

“This not only weaponizes the tax code and puts every taxpayer at risk, this lawsuit goes further and — for the first time — circumvents America’s democratic process by replacing the U.S. House’s voice with Nancy Pelosi’s voice,” Brady said in a statement.

The lawsuit, Docket No. 19-cv-1974, names as defendants the Treasury Department, the IRS, Treasury Secretary Steven Mnuchin and IRS Commissioner Charles Rettig.