Image copyright PA Media

Read through the 44-page defence provided by the Mail on Sunday to the High Court and you quickly realise why the Royal Family rarely resort to the courts in their endless struggles with the media.

Back in February last year the Mail on Sunday published excerpts from a letter that the Duchess of Sussex had written to her father, Thomas Markle, in August 2018. That letter referred to the period around her wedding to the Duke of Sussex in May the same year.

The publication of the letter by the Mail on Sunday followed hard on the heels of an article in the US-based People magazine where five people, who remain unnamed but are reported to be part of the duchess' inner circle, put her side of the story.

In that article it was suggested by a "long-time friend" that Thomas Markle refused to take Meghan or Prince Harry's calls and that he refused to get into a car sent to take him to the airport and then to the UK for the wedding.

"He knows how to get in touch," one friend is reported as saying. "Her telephone number hasn't changed. He's never called; he's never texted."

The article also referred to a letter that Meghan wrote to her father, asking him to stop criticising her.

It's the publication of that letter that the duchess is suing the Mail on Sunday over. She alleges breach of copyright, breach of data regulation laws and a breach of her right to privacy. She also alleges that the letter was selectively edited.

The Mail on Sunday pushes back on all three charges - it says that copyright applies to work that is the author's own intellectual creation; the letter was "pre-existing fact and admonishment" and as such is not protected under copyright law.

Image copyright Downtown Eastside Women's Center Image caption The Duchess of Sussex visited a women's centre in Vancouver on Tuesday

The newspaper says that, as the personal data considered topics that Meghan had herself put into the public domain, its processing and publication was not unlawful.

And it says that by becoming part of the British Royal Family - who "generate and rely on publicity about themselves… to maintain the privileged positions they hold" - there is rightly enormous public interest in her story.

But the Mail on Sunday's defence goes further - much further.

It notes that Meghan did not ask her father to keep the letter private.

It says the letter appears to have been "immaculately copied out" without "crossings-out or amendments" as if Meghan anticipated it being published.

It says the way the letter reads - "to put [Meghan] and her conduct in the best possible light" strongly suggests that that the duchess wanted or expected it to be read by others.

The Mail on Sunday accuses those friends of Meghan's who spoke to People magazine of lying. And it does so by citing Meghan's father, Thomas.

He says he did call and text his daughter in the weeks before the wedding, that he did tell her he couldn't make it to the wedding and that when after the wedding he tried to call her again, he was cut off by the couple.

The Mail on Sunday presents the publication of Meghan's letter to her father as his response to the lies that, he says, were put around by her friends in the People magazine article.

'Astonishing prospect'

Quite how much of the above is relevant to the actual case is up for debate. But the tone and content of the defence offered by the Mail on Sunday is a shot across the bows of Team Meghan.

It is a taster of what the Mail on Sunday will try to make the court case about - not centred on copyright law and data regulations, but about Meghan's character, her credibility, and the way she treats her family.

And standing in court, supporting the Mail on Sunday, could be her father Thomas - who is prepared to go to court, his daughter Samantha told the BBC.

It is an astonishing prospect - and a reminder of why the royals so rarely reach for their lawyers like this.