House Ways and Means Chairman Richard E. Neal issued subpoenas Friday for Treasury Secretary Steven Mnuchin and IRS Commissioner Charles Rettig to provide President Donald Trump’s tax returns.

The action takes to the next level a five-week-long dispute between the administration and Neal, D-Mass., who first asked on April 3 for six years of Trump’s personal tax returns, the returns for eight Trump companies and other tax information.

The subpoenas direct both Mnuchin and Rettig to appear before the committee at 5 p.m. on May 17 and produce the returns and other tax information,

A Treasury official acknowledged that the subpoenas had been received but made no further comment.

On Monday, Mnuchin rejected Neal’s request for the documents. In a letter to Neal, he wrote after consulting with the Department of Justice that he had determined that Neal’s request “lacks a legitimate legislative purpose.”

Neal, who addressed his legislative purpose for seeking the president’s tax returns in a pair of letters to Rettig, reiterated his purpose in a press release accompanying Friday’s subpoenas.

Neal noted that his April 3 request was part of his committee’s investigation into the IRS’s automatic annual audits of the president and whether those audits and the agency’s enforcement of federal tax laws pertaining to the president “need to be codified into federal law.” Currently, those audits are required by the Internal Revenue Manual, which was revised in 1977 to require the annual audits, according to a Joint Committee on Taxation history of the issue.

“I believed then, as I do now, that reviewing the requested documents is a necessary piece of the committee’s work,” Neal wrote. “Among other considerations, the committee wants to be sure that IRS employees who determine the scope of the President’s audit, or who determine whether to continue previously-initiated audits are protected in the course of their work.”

Neal made his request under Section 6103 of the tax code, which states that upon “written request” from the chairman of either of the two tax-writing committees, “the Secretary shall furnish such committee with any return or return information specified” in the request.

Neal and legal experts have predicted that the issue could lead to a lengthy court battle.

Possible paths forward

After Mnuchin’s rejection of Neal’s request, experts argued that Neal had three possible paths forward. Some attorneys speculated that the wording of Section 6103 is so unambiguous that Neal could have sued in federal district court. However, that would have been a risk because there hasn’t been a court case over this particular congressional power before, and courts have found that the legislative branch has its own constitutional powers to draw on when in conflict with the executive branch.

Other options would have been to schedule committee votes either on a resolution to hold Rettig, Mnuchin or both in contempt of Congress or on a resolution to approve a congressional subpoena.

Instead, Neal, who as chairman is the person empowered by the statute to demand tax returns from the IRS, proceeded with subpoenas signed by himself.

In his letter to Mnuchin and Rettig, Neal wrote that to date, “the IRS has failed to provide the return and the return information requested by my April 3, 2019 letter, despite an unambiguous legal obligation to do so.”

On Thursday, House Speaker Nancy Pelosi, D-Calif., suggested a floor vote holding Attorney General William Barr in contempt of Congress over Special Counsel Robert S. Mueller III’s report on 2016 election interference might wait until after seeing how a similar situation plays out with former White House counsel Don McGahn.

Pelosi may have foreshadowed the bundling of contempt votes when she added: “And we’ll just see, because there might be some other contempt-of-Congress issues that we’ll deal with at the same time.”

There has been a disconnect between Neal and the administration over who is authorized to turn over confidential tax return information. That appears to be reflected in Neal’s decision to issue subpoenas to both Mnuchin and Rettig.

While the statute empowering Neal to demand anyone’s tax return says “the Secretary” of the Treasury shall furnish the documents, Neal has addressed all of his letters to the IRS commissioner. That’s because for decades, by Treasury order, the commissioner has been delegated all authority in tax administration matters.

Although Rettig told a congressional panel last month he was aware of the delegation order, it has been Mnuchin who has answered Neal’s requests for the president’s tax returns.

The IRS code says removing a delegated power from the commissioner “may not take effect until 30 days after the Secretary notifies the Committees on Ways and Means” and five other House and Senate panels. That led House Financial Services Appropriations Chairman Mike Quigley, D-Ill., to maintain at a hearing last month that it is Rettig who must answer Neal’s letters, not Mnuchin, since no 30-day notice has been given.

Watch: Trump says, ‘We’re fighting all the subpoenas’