WASHINGTON (Reuters) - U.S. Treasury Secretary Steven Mnuchin said on Thursday that he would shield President Donald Trump’s tax returns from Congress, during remarks that could signal the administration’s approach to an expected request from congressional Democrats.

During testimony in the House of Representatives, Mnuchin told the House tax committee that he would follow the law upon receiving a request for tax returns but would also protect Trump’s privacy rights.

“I’m not aware if there’s ever been a request for an elected official’s tax return,” Mnuchin said in response to questions from Democratic Representative Lloyd Doggett, a member of the House Ways and Means Committee. “But we will follow the law and we will protect the president as we would protect any individual taxpayer under their rights.”

Committee Chairman Richard Neal, the only member of the House authorized by law to request the president’s returns, is expected to ask Mnuchin for the documents. A Democratic member of the committee said earlier this month he believed the panel would ask for Trump’s returns in a few weeks.

Democrats view the documents as a potential linchpin for oversight investigations, saying they would show whether the president has complied with U.S. tax law, profited from his own tax cuts, or has conflicts of interest from his vast business holdings.

Neal’s committee could seek both his personal and business returns.

Trump defied decades of precedent as a presidential candidate by refusing to release his tax documents and has continued to keep them under wraps as president, saying his returns were under audit by the Internal Revenue Service. The IRS has said that Trump can release his tax returns even while under audit.

Interest in Trump’s returns has soared since his former personal lawyer Michael Cohen told a House panel on Feb. 27 that the president has altered his value of assets and slashed the wages of his employees to lower his tax bills.

Section 6103 of the U.S. tax code allows the chairs of three committees -- Neal’s House panel, the Senate Finance Committee and the Joint Committee on Taxation -- to request confidential tax returns, and says the Treasury secretary “shall furnish” the documents.

But requesting the tax returns of a sitting president is unprecedented. Fearing a lengthy court battle for the documents, Neal’s committee has spent months working to develop a winning legal argument that could base the quest firmly within the panel’s jurisdiction to oversee the U.S. tax system.

Senator Chuck Grassley, the Republican chairman of the Senate Finance Committee, is also expected to seek Trump’s taxes if Democrats obtain them.

“There’s an awful lot of interest in 6103 today,” Mnuchin said. He said he would not speculate on a specific strategy for handling a request from lawmakers because he has not yet received one.