For nearly three years, the pillow entrepreneur Mike Lindell has been one of the leading financial supporters of the election denial movement, a tireless promoter of false claims that Donald J. Trump won the 2020 election and of efforts to change how Americans vote.

But recent public records, as well as interviews with Mr. Lindell and others, suggest that he is facing financial troubles.

Lawyers defending Mr. Lindell in several defamation lawsuits this week filed to withdraw from the cases, citing “millions” of dollars in unpaid fees. The withdrawal would leave Mr. Lindell without a lawyer in lawsuits where plaintiffs are seeking more than $1 billion in damages.

In an interview, Mr. Lindell said he didn’t blame his lawyers for dropping him. “They have to feed their families,” he said. He said that his activism related to the 2020 election had contributed to his financial woes.

In a filing late on Friday, Smartmatic, one of the firms suing Mr. Lindell for defamation, said it did not object to the withdrawal of lawyers but expressed concern that he was using the news “as an opportunity to fund-raise for his election fraud campaign.” The voting equipment firm noted that Mr. Lindell had already sent out a fund-raising email seeking $200,000 from supporters that invoked his lawyers’ motion.

Since 2021, Mr. Lindell, the chief executive of the bedding company MyPillow and a Trump associate, has financed conferences, legal efforts and even his own digital media venture to further unproven or debunked conspiracy theories regarding the use of voting machines to steal the 2020 election.

He has worked with state-level groups across the country, and continues to speak with activists on weekly conference calls. And he has used MyPillow advertising to support a range of conservative and right-wing media, including many outlets that amplify his claims.

Mr. Lindell says he has directly spent as much as $60 million on his political endeavors.

Days after Jan. 6, 2021, Mr. Lindell was photographed entering a brief meeting at the White House with Mr. Trump, carrying notes on which the phrase “martial law if necessary” was visible. That month, MyPillow lost brick-and-mortar distribution contracts with major big-box retailers. (The stores offered a variety of explanations unrelated to Mr. Lindell’s politics.) Last year, after Walmart pulled the company’s products from its stores, it recorded a loss of $7 million, according to Mr. Lindell. MyPillow is a private company, and these figures could not be independently verified.

Property records show that one of the two residences he owns through a limited-liability corporation is under an Internal Revenue Service lien for $4.6 million in unpaid taxes from 2020. Mr. Lindell said the lien was related to an ongoing negotiation over a tax write-off for an investment in a pharmaceutical company.

In April, an arbitration panel ordered Mr. Lindell to pay $5 million to a software engineer who took up Mr. Lindell’s challenge to debunk data he claims proves that the 2020 election was hacked. Mr. Lindell has refused to pay the engineer, Robert Zeidman, and both men have filed lawsuits over the matter.

In August, Mr. Lindell said, American Express cut his line of credit to $100,000 from $1 million, effectively ending his ability to pay his lawyers in the defamation suits. The decision, he said, was an “absolute hit job” related to his political activities, though he said the company had not said as much.

American Express did not comment on Mr. Lindell’s credit, but said in a statement that it “does not make customer decisions based on personal views or political affiliations. Our risk and underwriting models take into account a number of financial factors, including business inflows and outflows, and credit history.”

On Thursday, Andrew Parker, a lawyer at the Minneapolis firm Parker Daniels Kibort who has represented Mr. Lindell in many of his recent legal battles, filed motions to withdraw from the defamation suits filed by Dominion Voting Systems, Smartmatic, and Eric Coomer, the former director of product strategy and security at Dominion.

Mr. Parker did not respond to requests for comment. In court filings, he stated that Mr. Lindell started falling behind on payments early this year, and on Oct. 2, Mr. Lindell informed the firm that he and his company were “not able to get caught up or make any payment” on the “millions of dollars” owed to the firm.

Dominion also sued Fox News on similar grounds, and this April it reached a $787.5 million settlement with the media company. Asked if he had considered settling his own suit, Mr. Lindell said, “Absolutely not.”

It remains to be seen how Mr. Lindell’s finances will affect the broader election denial movement or the conservative news media, which he had helped finance on multiple fronts.

In emails and interviews, several influential activists said that Mr. Lindell continued to be an important figure in the movement, though some noted that their financial support came from other backers. Other donors contributed about one-third the cost of a conference Mr. Lindell hosted in Missouri in August, Mr. Lindell and other participating activists said.

MyPillow’s advertising and revenue-sharing agreements with conservative media have been a major source of support for right-wing figures, such as Stephen K. Bannon, the former Trump adviser who has a revenue-sharing agreement to promote MyPillow on his “War Room” podcast. Such promotions have increased slightly in the last year, according to the analytics companies iSpot.tv, which covers television advertising, and Magellan.ai, which covers podcasts.

Mr. Bannon has been highlighting Mr. Lindell’s financial woes on his show, portraying Mr. Lindell as the victim of corporate and government overreach and imploring viewers to buy more pillows to support him, which boosts sales. He is planning to host his show from Mr. Lindell’s Minnesota factory in the coming weeks, he said.

Susan Beachy contributed research.