By ANDREW TAYLOR and JONATHAN LEMIRE Associated Press

WASHINGTON (AP) — Treasury Secretary Steven Mnuchin has made it official: The administration won't be turning President Donald Trump's tax returns over to the Democratic-controlled House of Representatives.

Mnuchin tells Ways and Means Committee Chairman Richard Neal in a Monday letter that the committee's request "lacks a legitimate legislative purpose."

The move, which was expected, is sure to set in motion a legal battle over Trump's tax returns. The chief options available to Democrats now are to subpoena the IRS for the returns or to file a lawsuit.

Neal originally demanded access to Trump's tax returns in early April under a law that says the IRS to "shall furnish" the returns of any taxpayer to a handful of top lawmakers, including the chair of the tax writing Ways and Means committee.