Allegations by the Duchess of Sussex that articles published by a British newspaper were responsible for "causing" the dispute between her and her estranged father are "objectionable", the High Court has heard.
Lawyers for Associated Newspapers, publisher of the Mail on Sunday and MailOnline, said Meghan's contention that her "vulnerable" father was "harassed and humiliated", "manipulated" and "exploited" should not form part of her case.
The duchess is suing the publisher 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 Thomas Markle in August 2018.
At a preliminary hearing on Friday, conducted with the judge sitting in the Royal Courts of Justice and attended remotely by lawyers and reporters, the publisher's legal team asked for parts of the duchess's case to be "struck out".
Antony White QC, representing Associated Newspapers, told Mr Justice Warby that some of the allegations made by Meghan are irrelevant and not made with a proper legal basis.
He also said that the allegations relating to her father were made without any attempt to contact him, to see if he agrees with them.
In court documents prepared for the hearing, Mr White said the duchess alleges the publisher was "one of the 'tabloid' newspapers which had been deliberately seeking to dig or stir up issues between her and her father".
He said: "This is an allegation of seriously improper deliberate, i.e. intentional, conduct to the effect that the defendant's motive was to seek to manufacture or stoke a family dispute for the sake of having a good story or stories to publish."
Mr White argued that, such "complex tests of mental state" of the publisher are "irrelevant to the claim for misuse of private information", and asked the judge to strike out that allegation.
He added: "In this context it appears that the claimant has seen fit to put these allegations on the record without having spoken to Mr Markle, verifying these allegations with him or obtaining his consent (she admits ... that she has had no contact with him since the wedding).
"It is therefore highly unlikely that she has any credible basis for these allegations of impropriety towards him, or that proper particulars could be given."
Mr White also took issue with the duchess's allegation that the publisher "acted dishonestly" when deciding which parts of her letter to her father to publish.
He added: "It is extremely common for the media to summarise or edit documents when reporting current events, and that is not a basis for an allegation of dishonesty.
"It is open to the claimant to say, as she does, that the presentation of the letter was misleading - which is firmly denied - but there is no basis for her to allege that anyone working for the defendant was dishonest in the drafting and editing process."
In relation to an opinion piece by a handwriting expert, who analysed the letter, Mr White said that readers would have taken the comments in the article "more or less seriously depending on their own views of graphology".
He added: "It is not understood on what basis such comments are said to be unlawful - it is clearly not private information belonging to her - unless it be her case that the publication of any personal data about her that is unflattering is unlawful."
Mr White also said Associated Newspapers wrote to Meghan's lawyers on April 6, stating that Friday's hearing should be avoided if possible because of the Covid-19 pandemic, and offering not to seek costs if the disputed parts of her claim were withdrawn.
However, he said the duchess's legal team at Schillings law firm replied on April 16, saying she "considered it was unreasonable to accept the offer".
It is understood Harry and Meghan will join in to listen to the parts of the hearing conducted by her lawyers.
Sections of the letter were published in the newspaper and online in February last year, and it was announced the duchess would be bringing legal action in October.
The headline on the main article read: Revealed: The letter showing true tragedy of Meghan's rift with a father she says has 'broken her heart into a million pieces'.
The duchess is seeking damages from Associated Newspapers Ltd, the newspaper's publisher and operator of the website, 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.
The legal action was announced in a highly personal statement, in which the Duke of Sussex accused some newspapers of a "ruthless campaign" against his wife.
Referencing his mother Diana, Princess of Wales, who was a tabloid newspaper staple and died in a Paris car crash while being pursued by paparazzi in 1997, Harry said: "Though this action may not be the safe one, it is the right one.
"Because my deepest fear is history repeating itself. I've seen what happens when someone I love is commoditised to the point that they are no longer treated or seen as a real person.
"I lost my mother and now I watch my wife falling victim to the same powerful forces."
In the statement, on the duke and duchess's official website, Harry said of his wife: "I have been a silent witness to her private suffering for too long. To stand back and do nothing would be contrary to everything we believe in."
Mr Markle, 75, has claimed he felt pressured to share the letter after its contents were misrepresented in a magazine article.
In an interview with the Mail On Sunday, he said: "I have to defend myself. I only released parts of the letter because other parts were so painful. The letter didn't seem loving to me. I found it hurtful."
The first stage of the Duchess of Sussex's legal action against a British newspaper over its publication of a "private and confidential" letter to her estranged father is set to be heard at the High Court.