U.S. Rep. Richard Neal, a Springfield Democrat who has been under increasing pressure to use his power as a chairman to force the disclosure of President Donald Trump's tax returns, formally sent a request to the IRS on Wednesday seeking six-years of returns for the president.

The action, which Neal had promised he would take, sets up what could be a pitched battle between the House Ways and Means Committee and the White House.

Trump has resisted calls for him to release his tax returns, arguing that they were under audit.

The letter Neal sent to Internal Revenue Service Commissioner Charlies Rettig requests the individual tax returns for Trump from the years 2013 through 2018.

Neal is also seeking the returns for a number of holding companies and trusts affiliated with the president and confirmation from the IRS for each of Trump's individual returns that they had been the subject of an audit and for how long.

Neal's letter said his committee is considering the extent to which the IRS audits and enforces federal tax law against a president, and whether it should include a review of underlying business activities. The committee set a deadline of April 10 for the IRS to comply with the request.

Neal took over as chairman of the Ways and Means Committee for the first time in January when Democrats retook control of the House. Though he said he was interested in subpoenaing Trump's returns, he said wanted to proceed carefully.

A group called Need to Impeach, run by billionaire philanthropist and activist Tom Steyer, has been running ads and campaigning in Neal's western Massachusetts district to pressure him to make the tax request.

"If we're going to actually get investigations, impeachment and removal from office, we've got to get this show on the road," Steyer told the News Service in February. "The idea that we're doing this carefully and judiciously, I don't even know what that means. They have an absolute right to do this."