US President Donald Trump said House Republicans should vote to release the sex-trafficking files in the Jeffrey Epstein case, a startling reversal after previously fighting the proposal as a growing number of those in his own party supported it.

“We have nothing to hide, and it’s time to move on from this Democrat Hoax perpetrated by Radical Left Lunatics in order to deflect from the Great Success of the Republican Party,” Trump wrote on social media late on Sunday after landing at Joint Base Andrews following a weekend in Florida.

Trump's statement followed a fierce fight within the GOP over the files, including an increasingly nasty split with Georgia Representative Marjorie Taylor Greene, who had long been one of his fiercest supporters.

The president’s shift is an implicit acknowledgement that supporters of the measure have enough votes to pass it the House, although it has an unclear future in the Senate.

It is a rare example of Trump backtracking because of opposition within the GOP.

In his return to office and in his second term as president, Trump has largely consolidated power in the Republican Party.

“I DON’T CARE!” Trump wrote in his social media post. “All I do care about is that Republicans get BACK ON POINT.”

Lawmakers who support the bill have been predicting a big win in the House this week with a “deluge of Republicans” voting for it, bucking the GOP leadership and the president.

In his opposition to the proposal, Trump even reached out to two of the Republican lawmakers who signed it.

One, Colorado Representative Lauren Boebert, met last week with administration officials in the White House Situation Room to discuss it.

The bill would force the Justice Department to release all files and communications related to Epstein, as well as any information about the investigation into his death in federal prison.

Information about Epstein’s victims or ongoing federal investigations would be allowed to be redacted.

“There could be 100 or more” votes from Republicans, said Republican Representative Thomas Massie, among the lawmakers discussing the legislation on Sunday news show appearances.

“I'm hoping to get a veto-proof majority on this legislation when it comes up for a vote.”

Massie and his Democratic Party colleague Ro Khanna introduced a discharge petition in July to force a vote on their bill.

That is a rarely successful tool that allows a majority of members to bypass House leadership and force a floor vote.

Speaker Mike Johnson had panned the discharge petition effort and sent members home early for their August recess when the GOP's legislative agenda was upended in the clamouring for an Epstein vote.

Democrats also contend the seating of newly-elected colleague Adelita Grijalva was stalled to delay her becoming the 218th member to sign the petition and gain the threshold needed to force a vote.

She signed on moments after taking the oath of office last week.

Massie said Johnson, Trump and others who have been critical of his efforts would be “taking a big loss this week.”

“I'm not tired of winning yet, but we are winning,” Massie said.

The vote comes at a time when new documents are raising fresh questions about Epstein and his associates, including a 2019 email that Epstein wrote to a journalist that said Trump “knew about the girls”.

The White House has accused Democrats of selectively leaking the emails to smear the Republican president.

Trump has never been accused of wrongdoing in connection with Epstein and the mere inclusion of someone’s name in files from the investigation does not imply otherwise.

Epstein, who killed himself in jail in 2019 while awaiting trial, also had many prominent acquaintances in political and celebrity circles besides Trump.

Khanna voiced more modest expectations on the vote count than Massie.

Still, Khanna said he was hoping for 40 or more Republicans to join the effort.

“I don't even know how involved Trump was,” Khanna said. “There are a lot of other people involved who have to be held accountable.”

Khanna also asked Trump to meet with those who were abused.

Some will be at the Capitol on Tuesday for a news conference, he said.

Massie said Republican lawmakers who fear losing Trump's endorsement because of how they vote will have a mark on their record, if they vote “no”, that could hurt their political prospects in the long term.

“The record of this vote will last longer than Donald Trump's presidency," Massie said.

On the Republican side, three Republicans joined with Massie in signing the discharge petition: Marjorie Taylor Greene of Georgia, Nancy Mace of South Carolina and Boebert. (AP)