WASHINGTON (Reuters) - U.S. Treasury Secretary Steven Mnuchin on Tuesday denied he was breaking the law by refusing to turn over President Donald Trump’s tax returns and took aim at a Democratic lawmaker who has continued to press for the documents.

FILE PHOTO: U.S. Treasury Secretary Steven Mnuchin testifies before a Senate Finance Committee hearing on the President's FY2021 Budget on Capitol Hill in Washington, U.S., February 12, 2020. REUTERS/Yuri Gripas/File Photo

“I find it offensive that you’re telling me that I’m breaking the law and staggering lies,” Mnuchin said during a hearing held by the U.S. House of Representatives Ways and Means Committee on the Trump administration’s fiscal 2021 budget request.

The exchange came after over a year of legal battles between the panel and the Trump administration over the Republican president’s tax returns.

Mnuchin told the committee that he was relying on legal counsel and that the issue would be decided by the courts, not Congress.

“This is in the courts and the courts will deal with it,” he said in an exceptionally testy exchange with Representative Bill Pascrell, a New Jersey Democrat who insisted that U.S. laws require the Treasury to submit documents requested by Congress.

Pascrell said a member of Mnuchin’s staff member accused the lawmaker of being “intemperate” when he submitted written questions about reports that Mnuchin had provided private tax information about former Vice President Joe Biden to two Senate Republicans.

“Being lectured on civility from someone who works for the president - President Trump - is like taking chivalry lessons from Jack the Ripper,” Pascrell said. “It is impossible to be polite to corruption and people who break the law.”

The U.S. Justice Department in June said Mnuchin did not violate the law by refusing to provide Trump’s tax returns to Congress because the confidentiality of returns is protected under the law.

Ways and Means Committee Chairman Richard Neal had issued a subpoena demanding the administration turn over six years of Trump’s returns.

A federal judge in January put that bid on hold, saying he would wait for a much-anticipated appeals court decision relating to congressional subpoenas before issuing a ruling.

That court handed Trump a major victory last month when it dismissed a Democratic-led congressional panel’s lawsuit seeking to enforce a subpoena for testimony from former White House Counsel Donald McGahn.

Trump has refused to release his tax returns since he was a presidential candidate in 2016, breaking with a modern tradition set by contenders for the White House from both parties.