Treasury Secretary Steven Mnuchin Credit: Sarah Silbiger/The New York TimesWASHINGTON — The Treasury Department said on Monday that it would not release President Trump’s tax returns to Congress, defying a request from House Democrats and setting up a legal battle likely to be resolved by the Supreme Court.

WASHINGTON — The Treasury Department said on Monday that it would not release President Trump’s tax returns to Congress, defying a request from House Democrats and setting up a legal battle likely to be resolved by the Supreme Court.

Steven Mnuchin, the Treasury secretary, wrote in a letter to Representative Richard E. Neal, Democrat of Massachusetts and the chairman of the House Ways and Means Committee, that Mr. Neal’s request for the tax returns “lacks a legitimate legislative purpose” and that he was not authorized to disclose them. The decision came after weeks of delays as Mr. Mnuchin said that his department and the Justice Department needed to study the provision of the tax code that Democrats were […]