The US Congress has approved a measure to compel the US Justice Department to release all files pertaining to its investigation into convicted paedophile Jeffrey Epstein.

The bipartisan bill, which calls for the release of the files “in a searchable and downloadable format” within 30 days, passed the House of Representatives on Tuesday and the Senate agreed to pass it upon arrival.

It next needs the sign-off of President Donald Trump. The president urged Republicans in Congress on Monday to vote for the release – reversing course after his administration declined to make them public.

He had faced pushback from Epstein victims and a potential revolt from Republicans who would would vote to force the files’ release.

Congress’ lower chamber began debating the measure on Tuesday morning and voted within hours. Several of Epstein’s victims spent the day on Capitol Hill to advocate for the bill’s passage and to hold news conferences with reporters.

Nearly all the House lawmakers voted in favour of the resolution, which passed 427-1. Clay Higgins, a Republican lawmaker from Louisiana, was the only representative who voted against the bill. Two Republicans and three Democrats did not vote.

The House Oversight Committee have already made public thousands of documents from the Epstein estate relating to the late financier, but the resolution passed on Tuesday covers material currently in the possession of the justice department.

That material could, in theory, include files pertaining to imprisoned Epstein co-conspirator Ghislaine Maxwell, as well as people – including government officials – mentioned in the case. It could also include internal justice department documents.

The vote comes just two days after Trump wrote on Truth Social to encourage Republicans to vote for the measure. In the post, he argued that “we have nothing to hide”.

Before Trump’s post, some House Republicans had made clear they were willing to break ranks with the president and House Speaker Mike Johnson to vote in favour.

The Republican-controlled Senate quickly agreed to pass the measure on Tuesday evening.

Senate Majority Leader John Thune had previously suggested that while he was “not hearing” much desire from fellow Republicans to push for the release of the documents, a successful House vote could change that.

The Republican has been under enormous pressure from both sides of the US political spectrum and Senate minority leader Chuck Schumer requested unanimous consent on the Senate floor to “immediately” pass the bill to release all the unclassified files. No one objected so the measure was approved.

Another Republican, Senate Majority Whip John Barrasso, had previously told NBC’s Meet the Press only that the Senate would “take a look” at the bill if it passes the House.

“We’ll see what it says,” Barrasso said. “We all want accountability and transparency. But to me, this it not about the truth. It’s not about justice.”

“This is about an attempt by the Democrats to make President Trump a lame-duck president,” he added. “And I’m not going to aid and abet them in their efforts to do that.”

The bill will head from the Senate to President Trump, who has said he would sign it into law.

Speaking to reporters on Monday night, he said Republicans had “nothing to do with Epstein”.

“It’s really a Democrat problem,” he said. “The Democrats were Epstein’s friends, all of them.”

Trump went on to argue the Epstein scandal was a “hoax” distracting from “the greatness of what the Republican Party had accomplished over the last period of time”.

As the Senate agreed to pass the bill on Tuesday, Trump said that it didn’t matter to him and cast the whole thing as a distraction.

“I just don’t want Republicans to take their eyes off all of the Victories that we’ve had,” he wrote in a social media post, listing wins that ranged from the passage of his budget bill over the summer to the end of the 43-day government shutdown.

There are obstacles to the files being released even if Trump signs the bill.

The text of the document that went before the House, for example, noted that the attorney general could withhold or redact portions of records that contain personal information that “would constitute a clearly unwarranted invasion of personal privacy”.

“Simply letting anything out could reveal a lot of private information that’s not relevant or appropriate for public consumption,” Jonathan Entin, a constitutional law professor at Case Western Reserve University in Ohio, told the BBC.

“There may also be some issues about law enforcement techniques that the justice department might not want to be out there in the public domain,” he added.

The House bill also noted that the justice department can hold back any documents that “jeapordise an active federal investigation or ongoing prosecution, provided that such withholding is narrowly tailored and temporary”.

That could potentially lead to delays, given that President Trump has called for investigations into Epstein’s links with prominent Democrats, such as Bill Clinton and Larry Summers, “to determine what was going on with them, and him”.

“That’s a potential hurdle,” Prof Entin said. “If, in fact, this is a serious investigation, presumably the prosecutors will not want everything out there while they’re sorting out whether they bring charges.”

Doing so, he added, “might create some prejudicial publicity about targets of the investigation” that could ultimately lead to intense litigation if any indictments are brought.

For those who have campaigned for the release of the files, anything short of full disclosure is likely to spark further questions and even outrage.

Several Republican lawmakers have expressed concerns that Trump’s order to the justice department to investigate Epstein’s ties could slow the release of the files.

“I’m concerned that now he’s opening a flurry of investigations, and I believe they may be trying to use those investigations as a predicate for not releasing the files. That’s my concern,” Representative Thomas Massie said on Tuesday.

Representative Marjorie Taylor Greene, a Georgia Republican now in a public row with Trump over the files, has also said the documents may be “tied up” in Trump’s investigation into Democrats.

“I believe the country deserves transparency in these files,” Greene told CNN on Sunday.

“I have no idea what’s in the files. I can’t even guess,” Greene added. “But that is the question everyone is asking is – why fight this so hard?”