WASHINGTON ― Rep. Richard Neal (D-Mass.) can ask for copies of Donald Trump’s federal tax returns whenever he wants, but Neal is in no hurry and seemingly doesn’t care if Democrats don’t get the documents before the next election.

Though the law is clear that the treasury secretary is supposed to hand over any returns requested by the chairman of the House Ways and Means Committee, Treasury Secretary Steve Mnuchin has all but said he’ll disobey the law ― meaning there will be a court fight.

“I can’t substitute my timetable for the federal courts’,” said Neal, chairman of Ways and Means, when asked if he thought the case could be wrapped up by Election Day. “I’ve been very careful not to presuppose a timeline.”

Democrats said they’d make the request for Trump’s returns after regaining control of the House of Representatives, but they’ve waited nearly three months to follow through. Neal has said only that he will make the request sometime this year, and House Speaker Nancy Pelosi (D-Calif.) has backed his cautious approach.

Nobody knows how long a court case could take, though congressional Democrats generally say they figure it will take months if not a year. But there’s never been such a case before.

Neal can request any American’s tax info thanks to a specific section of the tax code that grants that power to the chairs of congressional tax committees. George Yin, a tax expert at the University of Virginia School of Law, said he is unaware of any instance of a treasury secretary refusing to comply with a request under the law, which Congress has rarely used since it was enacted in 1924.

Yin said November 2020 would be a significant deadline depending on how Democrats frame their request and their legal posture in the court case. Democrats could argue, for instance, that they want to see if the president has paid his taxes or if he has a conflict of interest, such as income from a company or foreign government with business before the U.S. government ― things that voters might want to know.

“If that’s what you’re trying to get, then you’d want to get that information before the election,” Yin said.

But if Democrats argue they need the documents to perform oversight of the Internal Revenue Service and how it implements tax laws, then the deadline would be less important. Either way, they’ll probably need to show the request has a “legitimate purpose” in line with their constitutional responsibilities of lawmaking and oversight.

Yin cited two previous instances in which the Supreme Court upheld congressional oversight power in cases involving subpoenas, one in 1880 and the other in 1927, that are probably not useful for gauging how long a tax return case might take today.

Trump was the first major presidential candidate in decades not to voluntarily release personal tax information, which can reveal details of his income sources, charitable giving and how much tax he pays. He’s also the first modern president not to divest from his businesses, meaning people or organizations can essentially pay him to try to influence policy.

Michael Cohen, Trump’s former lawyer, testified last month that the president has manipulated the value of his assets in order to borrow money and get favorable tax treatment, which could be considered criminal acts.

The law is simple ― Section 6103 of the federal tax code says the Ways and Means chairman can request tax information and that the treasury secretary “shall furnish such committee with any return or return information specified in such request,” which the committee can then vote to make public.