The family of President Donald J. Trump is suing to block publication of a bombshell memoir by the president’s niece.

Filed on June 23 by the president’s brother Robert S. Trump in Queens County (NY) Surrogate's Court, the suit seeks an order blocking Trump’s niece Mary L. Trump and her publisher, Simon & Schuster, from proceeding with the publication of Too Much and Never Enough: How My Family Created the World’s Most Dangerous Man, citing a sweeping confidentiality clause agreed to into in 2001, when the estate of the the president’s father, Fred Trump Sr., was settled.

On the Simon & Schuster website, the book is described as a “revelatory, authoritative portrait of Donald J. Trump and the toxic family that made him” and claims to explain how Trump "became the man who now threatens the world’s health, economic security, and social fabric.” Mary L. Trump is billed as a trained clinical psychologist as well as the president’s only niece. The book is scheduled for a July 28 publication.

"Mary Trump agreed that she would not publish a book regarding her relationship with Robert Trump or the other two relatives, her aunt Judge Maryanne Trump Barry, or her uncle President Donald Trump, without first receiving consent from all three of them," Trump family attorneys argue in the suit. "Independent of her waiver, there’s not an adequate remedy at law because no award of monetary damages can ameliorate the loss that will be suffered if Mary Trump is permitted to violate the settlement agreement and publish accounts of her relationship with her uncles and aunts without their consent. Accordingly, this situation requires entry of a preliminary injunction."

Documents appended to the filing include the text of the broad confidentiality clause at issue, which bars the parties and their agents, including Mary L. Trump, who signed the agreement, from “directly or indirectly” publishing or causing to be published “any diary, memoir, letter, story, photograph, interview, article, essay, account, or description or depiction of any kind whatsoever, whether fictionalized or not, concerning their litigation or relationship with [the Trump family]." The clause also states that, should such a breach occur, the offending parties consent to a “temporary or permanent injunction.”

Lawyers for the Trump family argue that confidentiality clause effectively gives the Trump family an “approval right” over Mary Trump's manuscript, and allows them to restrain publication to prevent irreparable injury. And because the agreement binds “agents,” Trump family attorneys argue, Simon & Schuster is also “properly bound” by any injunction.

In a statement, S&S officials disagreed. “As the plaintiff and his attorney well know, the courts take a dim view of prior restraint, and this attempt to block publication will meet the same fate as those that have gone before,” S&S officials said.

The latest court battle comes on the same day that Simon & Schuster published former National Security adviser John Bolton’s memoir of his time in the Trump administration, The Room Where It Happened, after a federal court last week rejected the president’s bid for a restraining order blocking publication.