WASHINGTON — President Trump and his businesses, seeking to brush back congressional investigators, sued the chairman of the House Oversight and Reform Committee on Monday to try to quash a congressional subpoena for their financial records.
The lawsuit, filed in Federal District Court here, argued that the committee’s chairman, Representative Elijah E. Cummings, Democrat of Maryland, had no legitimate legislative reason to subpoena an accounting company tied to the president, so his subpoena should be deemed invalid and unenforceable.
“The Democratic Party, with its newfound control of the U.S. House of Representatives, has declared all-out political war against President Donald J. Trump,” lawyers for the plaintiffs wrote in their complaint. “Subpoenas are their weapon of choice.”
The suit also seeks a court order blocking the accounting company, Mazars USA, from handing over the information, which it says would “expose plaintiffs’ confidential information.”
The suit, which is almost certain to face a stiff challenge in court, mirrors other efforts in recent weeks by personal lawyers for Mr. Trump and his businesses to block the Democratic-controlled House from gaining access to Mr. Trump’s finances. In each case, the lawyers have used vivid terms to paint Democrats as politically craven, out to abuse the powers of their office only to embarrass Mr. Trump politically.
If nothing else, the suits and countersuits could delay the release of the documents sought by Democrats.
“With this subpoena, the Oversight Committee is instead assuming the powers of the Department of Justice, investigating (dubious and partisan) allegations of illegal conduct by private individuals outside of government,” the lawyers wrote. “Its goal is to expose plaintiffs’ private financial information for the sake of exposure, with the hope that it will turn up something that Democrats can use as a political tool against the president now and in the 2020 election.”
Mr. Trump and his businesses were not party to the Democratic subpoena, which was sent to Mazars earlier this month seeking financial records and communications related to Mr. Trump and his businesses after Michael D. Cohen, Mr. Trump’s longtime fixer, told the Oversight Committee that his former boss had intentionally misrepresented his assets and liabilities to suit his needs. Inflating the value of assets would help the Trump Organization secure loans. Deflating the value of assets would minimize tax liability.
“The committee has full authority to investigate whether the president may have engaged in illegal conduct before and during his tenure in office, to determine whether he has undisclosed conflicts of interest that may impair his ability to make impartial policy decisions, to assess whether he is complying with the emoluments clauses of the Constitution, and to review whether he has accurately reported his finances to the Office of Government Ethics and other federal entities,” Mr. Cummings wrote in a memo to members of his committee at the time.
The accounting company, which prepared financial statements for loan applications for Mr. Trump, had indicated to the chairman that it would comply with an earlier, voluntary request for that information only if he issued a subpoena.
“Mazars USA will respect the legal process and fully comply with its legal obligations,” the company said in a statement last week.
Spokeswomen for Mr. Cummings and Mazars did not immediately reply to a request seeking comment.
After the subpoena was issued, lawyers representing Mr. Trump in the congressional inquiries, William S. Consovoy and Stefan Passantino, made arguments similar to those laid out in the lawsuit directly to Mazars, urging the company not to comply. Republicans on the Oversight committee have made similar arguments.
Mr. Cummings is not the only Democratic chairman pursuing details of Mr. Trump’s long-obscured finances. The Intelligence and Financial Services committees have each issued subpoenas to other financial institutions, including Deutsche Bank, a longtime lender to Mr. Trump’s businesses.
And the House Ways and Means Committee has demanded six years of tax returns filed by Mr. Trump and his businesses. The committee has set a Tuesday deadline for the Internal Revenue Service to comply with the demand, filed not by subpoena but under a provision in the tax code that says the I.R.S. “shall” comply.