The Treasury Department will not release President Trump's tax returns to House Ways and Means Committee Chairman Richard Neal, citing guidance from the Department of Justice, Treasury Secretary Steve Mnuchin wrote in a letter Monday.

"In reliance on the advice of the Department of Justice, I have determined that the committee's request lacks a legitimate legislative purpose, and pursuant to section 6103, the department is therefore not authorized to disclose the requested returns and return information," Mnuchin wrote.

Neal, citing a statute that gives the chairman of House Ways and Means the authority to obtain any individual's tax return, had demanded six years of Mr. Trump's taxes, giving Mnuchin a deadline of Monday to comply. Mr. Trump's personal attorney had suggested in a letter to Mnuchin in April that the Department of Justice should decide whether Mr. Trump's tax returns could be disclosed to Neal.

Get Breaking News Delivered to Your Inbox

Neal said in a statement Monday that he would "consult with counsel and determine the appropriate response."

Mnuchin told Neal the Justice Department will memorialize its advice in a legal opinion soon.

Neal formally requested Mr. Trump's tax returns April 3.