American singer-songwriter Britney Spears issued a cease-and-desist letter against sister Jamie Lynn Spears, following Jamie’s new memoir and promotional tour. The popstar called out her younger sister for “derogatorily” referencing her while promoting her new book Things I Should Have Said.

During an interview last week, Jamie Lynn shared stories of Britney’s childhood in interviews and her struggles with mental health while also making claims that Britney behaved "erratically" at times and once locked the two of them in a room with a knife.

According to People publication, in response, Britney’s lawyer Mathew Rosengart issued a cease-and-desist letter against Jamie Lynn regarding the book Things I Should Have Said, stating: “We write with some hesitation because the last thing Britney wants is to bring more attention to your ill-timed book and its misleading or outrageous claims about her.” the letter begins.

It further reads, "Although Britney has not read and does not intend to read your book, she and millions of her fans were shocked to see how you have exploited her for monetary gain. She will not tolerate it, nor should she."

The letter said, "You of all people know the abuse and wrongdoing Britney had to endure during the conservatorship, after initially growing up with a 'ruinous,' alcoholic father. In fact, your own book reportedly states that your father 'spent most of my life in that cycle of ruinous behavior. His bouts of drinking caused me periods of torment and sorrow.'"

"As I have previously stated, having endured a 13-year conservatorship that stripped her of civil rights and fundamental liberties, Britney will no longer be bullied by her father or anyone else." Britney’s attorney wrote in the letter.

"Britney was the family's breadwinner and she also otherwise supported you," the letter continued addressing Jamie Lynn Spears. "Publicly airing false or fantastical grievances is wrong, especially when designed to sell books. It is also potentially unlawful and defamatory."

Citing a Michelle Obama quote, Britney’s lawyer Mathew Rosengart further said that Britney will now follow the "when they go low, we go high" philosophy. The letter concludes by saying, “You recently reportedly stated that the book was ‘not about her’. She takes you at your word and we, therefore, demand that you cease and desist from referencing Britney derogatorily during your promotional campaign. If you fail to do so or defame her, Britney will be forced to consider and take all appropriate legal action.”

Popstar Britney Spears and sister Jamie Lynn Spears’ feud has been going on for a while now. The two have been publicly wrangling on social media, with the sisters clashing over claims in Jamie Lynn's memoir.

Also Read: Jamie Lynn Spears tearfully explains her strained relationship with Britney Spears – “I did take the steps to help”