Treasury Secretary Steve Mnuchin testifies about the budget during a Financial Services and General Government subcommittee hearing on May 15, 2019, on Capitol Hill. (Jacquelyn Martin/AP)

Treasury Secretary Steven Mnuchin said Wednesday that a confidential IRS memo does not undermine the agency’s justification for denying lawmakers’ request for President Trump’s tax returns.

Appearing in front of a House panel, Mnuchin said the Treasury Department and Department of Justice relied on separate legal reasoning for rejecting the House Ways and Means Committee request for six years of the president’s personal and business financial records.

A memo originating in the IRS chief counsel’s office, published by The Washington Post on Tuesday, said the “only basis” for denying tax returns to the committee would be invoking executive privilege. The administration has not invoked executive privilege to deny the request for Trump’s tax records.

Asked by a House Democrat whether the memo contradicts Treasury’s denial of the request, Mnuchin said: “I actually don’t believe that’s the case. . . . That memo is addressing a different issue, and is not addressing the issue that we and the Department of Justice looked at.

“The legal advice we have relied upon — and I understand there are three branches of government, and when it comes to constitutional issues, there could be different interpretations,” Mnuchin said in response to questions from Rep. Jennifer Wexton (D-Va.).

A Treasury statement provided earlier this week argued that the IRS memo did not address the constitutional questions raised by the House panel’s request, although some legal experts said the memo does address those questions.

Mnuchin has denied the returns by arguing that there is no legislative purpose for demanding them. But, according to the document, “the Secretary’s obligation to disclose return and return information would not be affected by the failure of a tax writing committee . . . to state a reason for the request.”

[Read the memo.]

Several legal experts have argued the memo undermines Treasury’s rejection of the tax returns.

“The memo writer’s interpretation is that the IRS has no wiggle room on this,” said Daniel Hemel, an assistant professor at the University of Chicago Law School. “Mnuchin is saying the House Ways and Means Committee has not asserted a legitimate legislative purpose. The memo says they don’t have to assert a legitimate legislative purpose — or any purpose at all.”

Mnuchin also said he read the memo on his way to the U.S. Capitol on Wednesday morning. He also said that IRS Commissioner Charles Rettig had not reviewed the memo.

“I haven’t reviewed it. I looked at it literally on the way up here: Someone handed me a printed copy of it. I would not describe that as, ‘I’ve reviewed it,’ ” Mnuchin said, adding that “it was not a letter that came to our attention earlier.”

Mnuchin added: “We’re trying to find out who wrote the memo, where it came from, when it was, and why it wasn’t distributed.”

Mnuchin added that he would provide the documents if ordered to by the courts. “If the third branch of government opines on Congress’s right, then we would obviously supply the documents,” Mnuchin said.

Both Treasury and the Justice Department have declined requests for copies of the Justice Department’s advice.