A US House of Representatives committee has a little more than a month to decide what to do with six years of Donald Trump’s tax returns, after a years-long court fight ended late on Wednesday with the records handed to Congress.

The supreme court ordered the release of Trump’s returns to the House ways and means committee last week, rejecting the former president’s plea. Trump has consistently accused the Democratic-led committee of being politically motivated.

The committee had been seeking returns spanning 2015 through 2020, which it says it needs in order to establish whether the Internal Revenue Service (IRS) is properly auditing presidential returns, and whether new legislation is needed.

A treasury spokesperson said the department “has complied with last week’s court decision”, though it declined to say if the committee had accessed the documents.

According to CNN, Democrats on the panel were due to be briefed on Thursday on the “legal ramifications on section of the tax law that … Neal used to request Trump’s tax returns” but would not immediately see the returns.

Neal “declined to say if he has seen” the returns himself, CNN said. Asked if Democrats would release the returns to the public, Neal said: “The next step is to have a meeting of the Democratic caucus.”

The House will soon slip from Democratic hands, although the party has retained control of the Senate. On Wednesday an aide told Reuters that Democrats on the Senate finance committee, the counterpart to the House ways and means, were considering their options on any action relating to Trump’s tax returns.

One House Republican indicated he expected the returns to become public one way or another. Tory Nehls of Texas, a member of the hard-right, Trump-supporting Freedom Caucus, tweeted: “The IRS just gave six years of Donald Trump’s tax returns to the House ways and means committee. How long until someone ‘leaks’ them?”

The House committee first requested Trump’s returns in 2019. Trump, who on 15 November began his third consecutive run for the presidency, dragged the issue through the court system.

It was long customary, though not required, for major party presidential candidates to release their tax records. Trump was the first such candidate in four decades not to do so.

Financial and taxation practices at the Trump Organization are now under scrutiny in criminal and civil cases in New York. On Thursday, attorneys began closing arguments in the criminal tax fraud case.

Earlier this month, the editorial board of the Washington Post said Trump’s records should be released because “voters should expect to know what financial conflicts of interest [candidates for president] might bring to the job.

“And in Mr Trump’s case … in addition to his tax records, he should have provided a detailed accounting of his holdings and interests. His refusal to do so became glaring as [he] pressed to reform the tax code in 2017. Americans could only guess how its provisions might personally enrich the president and his family.”

In her recent book, Confidence Man: The Making of Donald Trump and the Breaking of America, the New York Times reporter Maggie Haberman described how Trump came up with his excuse for not releasing his tax returns.

On his campaign plane, just before Super Tuesday, 1 March, in the 2016 Republican primary, Trump reportedly “thought for a second about how to ‘get myself out of this’ [and] leaned back, before snapping up to a sudden thought.

“‘Well, you know my taxes are under audit. I always get audited,’ Trump said … ‘So what I mean is, well I could just say, ‘I’ll release them when I’m no longer under audit. ’Cause I’ll never not be under audit.’”

Later, in a debate against his Democratic opponent, Hillary Clinton, Trump memorably answered the charge that he “didn’t pay any federal income tax” by saying: “That makes me smart.”

Haberman also reported that “Republicans who knew Trump in New York” never expected Trump to release his tax records, “speculating that he was more worried that people would see the actual amount of money he made than he was about scrutiny into his sources of income”.

Shortly before the 2020 election, the New York Times revealed that Trump had reported heavy losses over several years to offset hundreds of millions of dollars in income, according to reporting and trial testimony. That allowed him to pay very little in taxes.

Trump said: “Totally fake news, no. Actually I paid tax. And you’ll see that as soon as my tax returns – it’s under audit, they’ve been under audit for a long time. The [IRS] does not treat me well … they treat me very badly.”