The Duchess of Sussex has applied to the High Court to stop the publisher of the Daily Mail and Mail on Sunday from naming her five friends who spoke anonymously to a US magazine to defend her from tabloid “bullying”.

Meghan is suing Associated Newspapers, publisher of the two titles and MailOnline, over articles which featured parts of a “private and confidential” letter from the duchess to her estranged father, Thomas Markle.

The duchess has claimed that identifying her friends, who were interviewed but not named by People magazine, would be for “no reason other than clickbait and commercial gain” and would endanger their “mental wellbeing”.

The Mail on Sunday said the paper had “no intention” of identifying the friends in its next edition but the question of their anonymity should be considered by the court.

These five women are not on trial, and nor am I

In the article, published in February last year, they spoke out against the bullying the duchess said she has faced, and have only been identified in confidential court documents.

In a witness statement submitted as part of the application, Meghan said: “Associated Newspapers, the owner of the Daily Mail and the Mail on Sunday, is threatening to publish the names of five women – five private citizens – who made a choice on their own to speak anonymously with a US media outlet more than a year ago, to defend me from the bullying behaviour of Britain’s tabloid media.

“These five women are not on trial, and nor am I. The publisher of the Mail on Sunday is the one on trial. It is this publisher that acted unlawfully and is attempting to evade accountability; to create a circus and distract from the point of this case – that the Mail on Sunday unlawfully published my private letter.

For the Mail on Sunday to expose them in the public domain for no reason other than clickbait and commercial gain is vicious and poses a threat to their emotional and mental wellbeing

“Each of these women is a private citizen, young mother, and each has a basic right to privacy.

“Both the Mail on Sunday and the court system have their names on a confidential schedule, but for the Mail on Sunday to expose them in the public domain for no reason other than clickbait and commercial gain is vicious and poses a threat to their emotional and mental wellbeing.

“The Mail on Sunday is playing a media game with real lives.”

Meghan went on to say in her witness statement: “I respectfully ask the court to treat this legal matter with the sensitivity it deserves, and to prevent the publisher of the Mail on Sunday from breaking precedent and abusing the legal process by identifying these anonymous individuals – a privilege that these newspapers in fact rely upon to protect their own unnamed sources.”

A Mail on Sunday spokesman said: “To set the record straight, the Mail on Sunday had absolutely no intention of publishing the identities of the five friends this weekend. But their evidence is at the heart of the case and we see no reason why their identities should be kept secret.

“That is why we told the duchess’s lawyers last week that the question of their confidentiality should be properly considered by the court.”

Meghan is suing Associated Newspapers over five articles – two in the Mail on Sunday and three on MailOnline – which were published in February 2019 and reproduced parts of a handwritten letter she sent to Mr Markle, 75, in August 2018.

Lawyers acting for Associated Newspapers have argued that her five friends – identified only as A-E in court documents – brought the letter into the public domain when it was referred to for the first time in their US magazine interview.

A confidante told the American publication about its content: “She’s like ‘Dad, I’m so heartbroken. I love you. I have one father. Please stop victimising me through the media so we can repair our relationship’.”

The publisher’s defence document said: “Information in the People interview about the claimant’s relationship and dealings with her father, including the existence of the letter and a description of its contents and the claimant’s father’s letter in response, could only have come (directly or indirectly) from the claimant.”

It added that Mr Markle had revealed the letter to correct the “false” impression Meghan’s friends had given about his actions in their interview.

The duchess’s legal team have claimed in court documents that she did not know the article was due to appear, would not have agreed to the letter’s contents being revealed, and after its publication she phoned friend A to express “her distress”.

This latest development comes after court papers were leaked last week, before going into the public domain, which claimed that Meghan was left “unprotected by the institution” of the monarchy when attacked by the media and “prohibited from defending herself”.

The duchess is seeking damages, which she has said will be donated to an anti-bullying charity, from Associated Newspapers for alleged misuse of private information, copyright infringement and breach of the Data Protection Act.

Associated Newspapers wholly denies the allegations, particularly the claim that the letter was edited in any way that changed its meaning, and says it will hotly contest the case.

No date has been set for any further hearing in the case and it is not known when a full trial of the issues is expected to take place.