Nancy Pelosi said Democrats will begin to seek President Donald Trump’s tax returns - a move likely to prompt outrage from the White House - when they take control of the U.S. House of Representatives in January.

The House Ways and Means Committee will “take the first steps,” said Pelosi, who has the backing of her members to become the next speaker of the House in January.

“There is popular demand for the Congress to request the president’s tax returns,” she said, speaking to reporters. “I’m sure the White House will resist, so the question is where do we go from there.”

Trump defied decades of tradition when he refused to release his tax records while running for president and after taking office. There is no law or rule compelling a president or candidate to do so, but nearly every nominee and president since 1976 has done so.

Democrats have argued that Trump’s tax returns are crucial in determining whether his sprawling business operations present a conflict of interest. Trump opted not to divest from his business, but turned over control of day-to-day operations to his sons Donald Jr. and Eric.

Several committees expected to investigate Trump could find use for the returns.

The White House did not immediately respond to a request for comment about Pelosi’s remarks.

Reporting by Ginger Gibson