Republican lawmakers say they have been targeted by intimidation tactics, including death threats, from allies of Jim Jordan as his bid for the US House of Representatives speakership falters.
Several Republicans told reporters they had been subject to a pressure campaign by supporters of Mr Jordan, who lost a second vote for the gavel on Wednesday.
Mr Jordan, a right-wing Republican from Ohio, has condemned the threats.
A hardline conservative revolt ousted the last Speaker on 3 October.
A third vote to elect a Speaker is expected on Thursday, and Mr Jordan will need to win around more colleagues in his party to secure the 217 votes needed to win the job.
Marianne Miller-Meeks, an Iowa Republican, wrote in a statement on Wednesday that she had "received credible death threats and a barrage of threatening calls" after voting for an alternative to Mr Jordan.
"One thing I cannot stomach, or support is a bully," she wrote.
Don Bacon, a Nebraska Republican who is a particularly vocal opponent of Mr Jordan, provided texts to Politico that appeared to show his wife being harassed by a supporter of the would-be Speaker.
"Your husband will not hold any political office ever again," one of the anonymous messages read. "What a disappoint [sic] and failure he is."
Mr Jordan denied any involvement in the pressure campaign.
"No American should accost another for their beliefs," he wrote on X, formerly known as Twitter, on Wednesday evening. "We condemn all threats against our colleagues and it is imperative that we come together."
"Stop. It's abhorrent," he added.
More than a handful of anti-Jordan Republicans, including Virginia's Jen Kiggans, Kay Granger of Texas and Florida's John Rutherford, complained of inappropriate persuasion tactics from local conservative leaders and right-wing influencers backing Mr Jordan.
"Intimidation and threats will not change my position," wrote Ms Kiggans on X.
Though none suggested Mr Jordan himself was directly involved, some placed blame for the tactics at his feet.
Carlos Gimenez, a Florida Republican, told NBC News he had brought up the matter directly with Mr Jordan, saying: "I don't really take well to threats."
"He told me that he wasn't behind it, and he's asked people to stop, but if you've asked people to stop it why aren't they listening to you?" Mr Gimenez said.
He said his office had been receiving robocalls about his opposition to Jordan.
Arkansas Republican Steve Womack criticised what he referred to as the "attack, attack, attack" tactics of Jordan allies against those lawmakers who have opposed his speakership bid.
And even some of Mr Jordan's allies, including Byron Donalds of Florida, acknowledged that the strong-arm approach may have "backfired".
"I think it was to the detriment of Jim," Mr Donalds told reporters.
The infighting comes after Mr Jordan failed for a second time to gain enough support from his party to clinch the speakership.
On Wednesday, 22 of his fellow Republicans voted against him - two more than did so in the first vote on Tuesday.
There is no end in sight to the leadership battle more than two weeks after Kevin McCarthy was removed as leader of the lower chamber of Congress in a backbench mutiny.
Without a Speaker, the Republican-controlled House is unable to pass any bills or approve White House requests for emergency aid. That includes potential help for Israel amid its war with Hamas.
Democrats, the minority party in that chamber, have been voting unanimously each time for their own leader, Hakeem Jeffries of New York.
As frustration mounts, talk has grown in the House of empowering acting Speaker Patrick McHenry for a temporary period of up to 90 days.
