New papers related to the case were filed to the High Court in London this week

Meghan Markle’s legal case against Associated Newspapers — publisher of the Mail on Sunday — looks set to pitch her against her father, Thomas Markle, 75.

In papers filed at the High Court in London on Tuesday, the newspaper group detailed its defense case against Meghan, 38, who is suing the Mail on Sunday for publishing extracts of a “private and confidential” letter sent to her dad in August 2018 — three months after her wedding to Prince Harry.

Within the court documents — which have been seen by PEOPLE — the newspaper group defends its right to publish the letter on the grounds that “there is a huge and legitimate public interest in the royal family and the activities, conduct and standards of behavior of its members.

“This extends not merely to their public conduct, but to their personal and family relationships because those are integral to the proper functioning of the monarchy.”

Meghan, Duchess of Sussex
Credit: Samir Hussein/WireImage

The filing continues, “Members of the royal family, including the Claimant (Meghan), generate and rely on publicity about themselves and their lives in order to maintain the privileged positions they hold and to promote themselves, their fulfilment of their duties and functions, and the good causes they have espoused.”

Meghan and harry
Meghan Markle and Prince Harry
| Credit: Rosa Woods/Getty

The document also makes extensive reference to the PEOPLE cover story The Truth About Meghan, published on February 18, 2018. A letter Meghan wrote to her father was referenced in the PEOPLE story, which the court documents cite. In the story, five women who form an essential part of Meghan’s inner circle say they spoke with PEOPLE to “stand up against the global bullying we are seeing and speak the truth about our friend,” as one longtime friend put it last February.

According to High Court papers submitted in October by Meghan’s legal team, the letter was sent by the Duchess of Sussex at a “time of great personal anguish and distress.”

Thomas Markle
| Credit: Good Morning Britain/ITV

The court papers filed by Associated Newspapers argue that the newspaper’s publication of excerpts from the letter was in “response” to the PEOPLE story in order to report Thomas Markle’s perspective.

Meghan is seeking damages from Associated Newspapers Ltd. for “alleged misuse of private information, copyright infringement, and breach of the Data Protection Act.”

The Schillings law firm representing the Duchess also claims the Mail on Sunday deliberately chose to “omit or suppress” important sections of the letter in an effort to hide the true meaning of Meghan’s words — something the news outlet denies in Tuesday’s filing.