The White House tried to silence criticism of President  Trump by threatening MSNBC co-hosts Joe Scarborough and Mika Brzezinski with an unflattering story in a supermarket tabloid, the two alleged Friday, as the Twitter war between the television personalities and the president escalated.

“Donald Trump is not well,” declared the headline of a Washington Post op-ed column the two wrote and then used as talking points during a lengthy segment of their show, “Morning Joe.”

In the column and on the program they said the White House used the threat of a National Enquirer story about their relationship as leverage to extract an apology for on-air criticism of the president.

The clash with the MSNBC hosts is the latest flare of tension between Trump and the news media that covers him. Earlier this week, the White House portrayed CNN as a source of “fake news” after the network retracted a story about an alleged tie between people close to Trump and Russia. Three CNN journalists resigned after the story was withdrawn.

Scarborough and Brzezinski were scheduled to be on vacation, but came on the air to address the president’s behavior at the top of the second hour of their program. They denied allegations Trump made about them in tweets on Thursday and condemned his behavior.

“He appears to have a fragile, impetuous, childlike ego that we have seen over and over again – especially with women. He can’t take it,” Brzezinski said on the program.

Scarborough and Brzezinski wrote that they think the president is “unmoored” and said he has “a disturbing obsession with Mika.”

In messages on Twitter on Thursday, Trump called Brzezinski “low I.Q. Crazy Mika” and Scarborough “Psycho Joe.” Trump also claimed that he had at one point seen Brzezinski “bleeding badly from a face-lift.”

Dozens of members of Congress, including many leading Republicans, criticized Trump for those tweets Thursday, saying they were beneath the dignity of his office and undermined his agenda.

Even some of Trump’s staunchest supporters in the media, including conservative radio commentator Rush Limbaugh and Fox News host Sean Hannity, said the tweets were ill-advised.

Seemingly undeterred, Trump returned to the fray Friday with a new tweet about the pair.

In Thursday’s tweets, Trump also said that the pair had invited themselves to Mar-a-Lago, his private club in Palm Beach, Fla., over the New Year’s holiday and that he refused to see them.

“That is laughable,” they wrote in the op-ed. Trump had invited them to dinner on Dec. 30, and Scarborough attended because Brzezinski did not want to go, they wrote.

“After listening to the president-elect talk about his foreign policy plans, Joe was asked by a disappointed Mr. Trump the next day if Mika could also visit Mar-a-Lago that night,” they wrote.

“She reluctantly agreed to go. After we arrived, the president-elect pulled us into his family’s living quarters with his wife, Melania, where we had a pleasant conversation. We politely declined his repeated invitations to attend a New Year’s Eve party, and we were back in our car within 15 minutes.”

The claim that Brzezinski was “bleeding badly from a face-lift is also a lie,” they wrote.

“Putting aside Mr. Trump’s never-ending obsession with women’s blood, Mika and her face were perfectly intact, as pictures from that night reveal,” they wrote.

“And though it is no one’s business, the president’s petulant personal attack against yet another woman’s looks compels us to report that Mika has never had a face-lift. If she had, it would be evident to anyone watching ‘Morning Joe’ on their high-definition TV. She did have a little skin under her chin tweaked, but this was hardly a state secret. Her mother suggested she do so, and all those around her were aware of this mundane fact.”

On his show, Scarborough said Trump “attacks women because he fears women.” He described a conversation with a member of Congress who recounted how Trump once described Brzezinski as having blood coming out of her eyes and ears – a remark similar to what Trump said about Megyn Kelly, the former Fox News anchor, following the August 2015 Republican primary debate. Trump made the remark about Brzezinski in a meeting with 20 members of Congress, Scarborough said.

Scarborough also described several calls from the White House in which he was told the National Enquirer was preparing an unflattering story about his relationship with Brzezinski. Scarborough and Brzezinski, who are both divorced, have been romantically linked for years but only went public with their relationship in May after they got engaged.

Scarborough said he was told that if they called Trump and “apologize for your coverage, he will pick up the phone and basically spike the story.”

David Pecker, the chief executive of American Media – the company that owns the National Enquirer – is a friend of the president’s. Scarborough said Trump told him during the 2016 campaign that the paper ran negative stories about his Republican opponents.

Brzezinski said the Enquirer was calling her teenage children and were “pinning the story on my ex-husband.”

When Scarborough had a conversation about the story with the White House, Brzezinski said her co-host was told, “This can go away.”

An MSNBC representative said Scarborough and Brzezinski made executives at the network aware of the situation with the White House and the Enquirer in April when the conversations began.

The Enquirer defended its story and said it had no knowledge of involvement by the White House.

“At the beginning of June, we accurately reported a story that recounted the relationship between Joe Scarborough and Mika Brzezinski, the truth of which is not in dispute,” American Media chief content officer and Vice President Dylan Howard said in a statement.

“At no time did we threaten either Joe or Mika or their children in connection with our reporting on the story. We have no knowledge of any discussions between the White House and Joe and Mika about our story, and absolutely no involvement in those discussions.”

Trump tweeted Friday morning that Scarborough had called him and asked to have the Enquirer story killed.

“Watched low rated @Morning-Joe for first time in long time. FAKE NEWS. He called me to stop a National Enquirer article. I said no! Bad show.”

Scarborough responded on Twitter, saying he had texts and call records that back his claim that the White House tried to use the Enquirer story to extract an apology for tough coverage.

“I have texts from your top aides and phone records. Also, those records show I haven’t spoken with you in many months,” he wrote.

MSNBC, at Scarborough’s request, is not confirming which White House aides discussed the Enquirer story with him. The network also declined to release the text messages that Scarborough said he has.

White House deputy press secretary Sarah Huckabee Sanders defended Trump’s tweet Thursday, claiming that the president was fighting back against a steady barrage of on-air insults from Brzezinski and Scarborough.

On Friday, she brushed aside a question about the continued controversy during a short, off-camera briefing with reporters.

In an April 13 interview with the Los Angeles Times, Brzezinski and Scarborough noted that their once-cordial relationship with Trump had deteriorated since the inauguration as they have expressed dismay at what they think has been a chaotic, undisciplined presidency.

“Morning Joe” was considered one of the friendlier TV forums for Trump during the 2016 presidential campaign.