Pressure is building, with an ABC News/Washington Post poll showing a healthy majority of Americans support the move. Tax March, a coalition of liberal groups, has been pressuring Democrats to hurry up, and Democratic members of the Congressional Progressive Caucus have been getting antsy , too.

Trump was the first major presidential candidate in 40 years not to release tax returns, which would have revealed detailed information about his sources of income and how much tax he pays. Democrats vowed to get the returns themselves, but haven’t done it yet.

Democrats have had the power to request Trump’s tax returns from the Internal Revenue Service since they assumed control of the House this year, but they’ve hesitated. To build the public case for disclosure, the House tax committee’s oversight panel will examine its authority to obtain the president’s tax returns at a Feb. 7 hearing.

The secrecy of President Donald Trump ’s tax returns will be the subject of a hearing next week, Democrats in the House of Representatives announced Thursday.

Rep. Richard Neal (D-Mass.), the chairman of the tax committee, has said he wants time “to lay out a case” for the move and that staffers drafting the request are doing it “methodically” and need time.

Trump’s tax returns could show whether he evaded taxes, as a blockbuster New York Times report alleged that he and his father, Fred Trump, did for decades in the 20th century. The returns could also provide information about the sources of financing and debt at his multi-billion dollar real estate business.

As part of the public case, Democrats introduced legislation by Reps. Bill Pascrell (D-N.J.) and Anna Eshoo (D-Calif.) that would require presidential candidates to disclose 10 years of tax returns.

“Before 2016, presidential candidates routinely disclosed their tax returns,” Pascrell and Eshoo said in a statement. “Donald Trump refused to clear that low bar, and as a result, the American people remain in the dark about the extent of his financial entanglements and potential conflicts of interest.”

The legislation will be part of the hearing, but the big topic will be how Democrats present their case to obtain Trump’s tax returns. Pascrell has sought Trump’s tax returns since February 2017 through resolutions invoking Section 6103 of the tax code. This provision allows the committee to obtain any individual’s tax returns from the IRS for the purposes of an investigation. Republicans on the committee have blocked Pascrell’s resolutions more than a dozen times. All the chairman has to do, though, is send a request to the IRS.

Treasury Secretary Steve Mnuchin has hinted that he will not comply with the Democrats’ request, which could get tied up in court for months.

Committee Democrats previously told HuffPost that they would get Trump’s tax returns if they won a House majority in the 2018 midterm elections. This hearing is the first step in that process.