Treasury Secretary Steve Mnuchin says battle over President Trump's tax returns could go to court Differences "go to the third branch of government to be resolved," he said.

Treasury Secretary Steven Mnuchin on Wednesday accused congressional Democrats of "weaponizing the IRS" by trying to obtain President Donald Trump's tax returns and suggested the battle may ultimately have to be decided by the courts.

“Mr. Secretary, doesn’t Congress as a separate branch of government have a legitimate interest in determining whether or not the IRS is enforcing tax laws with respect to the President of the United States?" Sen. Chris Van Hollen, a Maryland Democrat, asked Mnuchin at a Capitol Hill hearing. He was referring to the law that requires the IRS to audit every president's tax returns.

Mnuchin responded: "Mr. Senator, I want to be respectful in answering this and I’m not trying to avoid your question, but the answer is that there is a difference in interpretation between Congress and us and the Department of Justice around this law that not only impacts the president and this Congress but has a very big impact on every single taxpayer in weaponizing the IRS."

"And this is why there are three branches of government so if there is a difference of opinion, this will go to the third branch of government to be resolved," he said.

Mnuchin was testifying before a Senate Appropriations subcommittee just two days ahead of Friday's deadline set by the Rep. Richard Neal, the Democratic chairman of the House Ways and Means Committee, for Mnuchin and IRS Commissioner Charles Rettig to respond to a subpoena for six years of the president's tax returns. The request came after Mnuchin rejected an earlier request by Neal.

"First of all, we haven't made a decision, but I think you can guess which way we are leaning on our subpoena," Mnuchin said. "To the extent that we don't and there is litigation, I take great comfort that there's a third branch of government to deal with this important issue."

The president’s lawyers and White House are expected to challenge the move and have argued that Democrats’ request does not serve a legitimate legislative purpose, an argument the administration made in its rejection of the Democrats’ initial request.

The committee chairman, Sen. John Kennedy, R-La., pushed back against Van Hollen's line of questioning regarding Trump's tax returns by laying out a scenario where a member of Congress could try to obtain anyone's returns.

"How about you send me all the tax returns from every candidate among my Democratic friends running for the president of the United States? Now, I'm not interested in it for political reasons, I just want to study the IRS and I think I'll start with these returns. How much confidence do you think the American people will have in the internal revenue service and the privacy concerns if we start doing that in this country?" Kennedy said.

Mnuchin said he thought that "would be very dangerous."

"I think it would also be very dangerous to provide you with returns of large Democrats or Republicans who made political gifts, or leaders of industry, or leaders of labor unions," Mnuchin said.