A federal judge for the U.S. District Court for the District of Columbia has ruled against blocking a congressional committee’s subpoena of President Trump’s accounting firm for his financial information.

Judge Amit Mehta’s decision also denied a stay, pending appeal, that Trump had asked for to temporarily halt the subpoena. The decision represents a major blow to the president’s legal argument that Congress cannot investigate his finances and whether or not he committed a crime.

Trump’s legal team argued that the House Oversight and Reform Committee does not have a legitimate legislative or oversight purpose in subpoenaing Trump’s accounting firm, Mazars USA, for the information.

A member of Trump's legal team confirmed that the president will appeal the decision.

"We will be filing a time appeal to the DC Circuit Court of Appeals," Sekulow told the Washington Examiner in an email.

Mehta found that the committee's reasons for requesting the document are “facially valid legislative purposes, and it is not for the court to question whether the Committee’s actions are truly motivated by political considerations."

The judge also noted that Congress investigated former Presidents Richard Nixon and Bill Clinton before initiating impeachment proceedings and “plainly views itself as having sweeping authority to investigate illegal conduct of a president, before and after taking office.”

“This court is not prepared to roll back the tide of history,” he said.

The subpoena seeks to compel the accounting firm, Mazars USA, to turn over four categories of documents related to the president and four affiliated entities, including the Trump Organization and the Trump Foundation.

The case could have ripple effects for other investigations into Trump’s finances, like parallel subpoenas from the House Financial Services and Intelligence Committees to Deutsche Bank and Capitol One Bank for Trump’s borrowing and account information or the House Ways and Means Committee’s request and subpoena for tax information of Trump and his businesses from the Treasury Department and IRS.

Trump has vowed to fight all subpoenas and investigatory requests from Congress. But Mazars will have only seven days to comply with the subpoena now that the ruling has been made, and Trump's request for a stay on the subpoena, pending appeal, was rejected.

Jennifer Farrington, a spokesperson for the firm, said in an email: "Mazars USA will respect the legal process and fully comply with its legal obligations. We believe strongly in the ethical and professional rules and regulations that govern our industry, our work and our client interactions."

Farrington added: "As a matter of firm policy and professional rules we do not comment on the work we conduct for our clients."

Committee Chairman Elijah Cummings, D-Md., decided to issue the subpoena to Mazars following the testimony of Michael Cohen, the president’s former lawyer and so-called “fixer.”

“Today’s decision is a resounding victory for the rule of law and our Constitutional system of checks and balances," Cummings said in a release. "The court recognized the basic, but crucial fact that Congress has authority to conduct investigations as part of our core function under the Constitution."

During testimony before the panel, Cohen claimed Trump’s financial statements were altered to falsely show his assets and liabilities. Cohen turned over to the committee parts of Trump’s financial statements from 2011, 2012, and 2013, some of which were prepared by Mazars.

“At a minimum, such an investigation is justified based on Congress’s ‘informing function,’ that is, its power ‘to inquire into and publicize corruption,’” Mehta wrote. “It is simply not fathomable that a Constitution that grants Congress the power to remove a President for reasons including criminal behavior would deny Congress the power to investigate him for unlawful conduct — past or present — even without formally opening an impeachment inquiry."

Mehta went on to cite changes to the tax code made by Congress following the Teapot Dome Scandal, unocovered in 1924, which involved bribes to a cabinet official. Those changes allowed congressional committee chairs to review the tax returns and information of individuals and companies, and is the same law that Ways and Means Committee Chairman Richard Neal, D-Mass., cited in his request to review Trump's tax returns.

The judge noted that Congress gave itself that power after an investigation, and could make similar legal changes after its current investigations, meaning he found that Congress could have a legitimate legislative purpose in those inquiries.

“This court is in no position that say that an equally ambitious legislative agenda might not arise out of the current era of congressional investigations of the presidency,” he wrote in his decision.