Steve Bannon’s main financial backer, conservative donor Rebekah Mercer, cut ties with him Thursday shortly after she spoke by phone with President Donald Trump, according to two people familiar with the call.

But there was no sign that the White House has succeeded in pushing Bannon out of his leadership of the conservative Breitbart News website. Insiders said he was doing business as usual there on Thursday and showed no signs of leaving the organization.

Still, the rebuke from a former close ally of Bannon shows the deepening rift between Trump and his former chief strategist following release of excerpts from a book by author Michael Wolff in which Bannon is quoted criticizing the president and insulting the Trump family. Among other statements, he called meetings between Trump family members and Russian operatives during the election campaign ”treasonous” and “unpatriotic.”

Mercer and her father, investor Robert Mercer, former co-chief executive officer of the hedge fund Renaissance Technologies, are among the the most important financial supporters of conservative Republican causes and a key source of Bannon’s influence.

Rebekah Mercer and Trump spoke by phone Thursday afternoon, said the two people, who spoke on condition of anonymity to describe the private call. Shortly afterward, Mercer issued the statement.

"I support President Trump and the platform upon which he was elected," Mercer said in the statement. "My family and I have not communicated with Steve Bannon in many months and have provided no financial support to his political agenda, nor do we support his recent actions and statements."

In the years leading up to the 2016 election, Bannon became a close political adviser to the Mercers and directed their wealth to a series of interlocking projects that advanced his populist brand of politics.

They extended a financial lifeline to Breitbart, allowing Bannon to build it into a conservative juggernaut. Their family foundation funded another Bannon project, the 2015 book "Clinton Cash," which presaged Trump’s "Crooked Hillary" label; and they invested in Cambridge Analytica, a data firm Trump used to target voters in the race’s final months.

Since 2006, the Mercers have given $41.5 million to Republican candidates, committees and super PACs, including $2 million to Make America Number 1, which supported Trump in the general election, according to Federal Election Commission records. Rebekah Mercer gave $449,000 in June 2016 to Trump Victory, a joint fundraising committee that benefited Trump’s campaign, the Republican National Committee and state party committees.

From 2013 to 2015, the Mercer Family Foundation gave $31.4 million to conservative groups, with other beneficiaries including the Federalist Society, the Heritage Foundation, the Heartland Institute and the Cato Institute, according to the foundation’s tax returns.

Trump denounced his former strategist, who was ousted from the White House in August, hours after The Guardian published the first excerpts from Woolf’s book, "Fire and Fury," on Wednesday. “When he was fired, he not only lost his job, he lost his mind,” Trump said in a statement.

Trump’s lawyers later sent Bannon a cease-and-desist letter, threatening legal action and accusing him of violating a non-disclosure agreement. The president’s legal team also demanded that Wolff’s publisher, Henry Holt and Co., stop distribution, which had been scheduled to begin next week. Instead, the company moved up publication - to Friday.

White House Press Secretary Sarah Sanders publicly suggested Bannon be dismissed from his position at Breitbart. Asked Thursday whether the conservative media organization should oust Bannon, Sanders responded, “I certainly think it should be something that they look at.”

Bannon is quoted in "Fire and Fury" as saying that Special Counsel Robert Mueller will “crack Don Junior like an egg on national TV,” over the president’s son’s meeting with a Russian lawyer at Trump Tower in June 2016. Bannon also called Donald Trump Jr.’s meeting with the lawyer, in which he expected to receive damaging information on Trump’s election opponent Hillary Clinton, “treasonous” and “unpatriotic.” Trump’s son-in-law Jared Kushner also attended the meeting.

Bannon also described Kushner’s business deals as “greasy” and suggested he would be vulnerable to a money-laundering investigation.