Washington — Rep. Richard Neal, the House Ways and Means Committee chairman, on Saturday set a new deadline for the IRS to furnish President Trump's tax returns: 5 p.m. on Tuesday, April 23.

"I am aware that concerns have been raised regarding my request and the authority of the Committee," Neal wrote to IRS Commissioner Charles Rettig. "Those concerns lack merit. Moreover, judicial precedent commands that none of the concerns raised can legitimately be used to deny the Committee's request."

Neal argued the statute used in his request, Section 6103, was "unambiguous and raises no complicated legal issues that warrant supervision or review" by either the Treasury Department or the Justice Department.

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Treasury Secretary Steven Mnuchin responded to the request for six years of the president's taxes by saying he would not be able to review the request for the president's tax returns by April 10, the original deadline set by Neal. Mnuchin called it an "unprecedented" move that raises questions about the scope of Congress' "investigative authority" and lawmakers' "legislative purpose."

Neal said his agency was consulting with the Justice Department to determine whether the request for Mr. Trump's tax returns is legal and constitutional.

The Ways and Means chairman also cited the Supreme Court, which, he argued, has noted that congressional motivations "are not to be second guessed, even by the courts." And he said that concerns about what the committee might do with the information in the president's tax returns were "baseless."

Last week, Neal sent a formal request to the IRS for Mr. Trump's tax returns, arguing the committee "has a responsibility to conduct oversight of our voluntary Federal tax system and determine how Americans — including those elected to our highest office — are complying with those laws."

The president responded by saying he's under audit — a pretext he has often cited — and "would not be inclined" to release his returns until the audit is completed. No federal statute bars individuals under audit from releasing their tax returns. Mr. Trump's lawyer in the matter, Will Consovoy, also asked the IRS not to hand over the president's tax returns until it receives a legal opinion from the Justice Department.

Last weekend, Mick Mulvaney, who is the acting White House chief of staff, told Fox News that Democrats would "never" see Mr. Trump's tax returns.

Rebecca Kaplan and Camilo Montoya-Galvez contributed to this report.