The Duchess of Sussex is bringing a bid to postpone the trial of her High Court privacy action against the Mail On Sunday over the publication of a letter to her estranged father.

Meghan is suing Associated Newspapers Ltd (ANL), publisher of the Mail On Sunday and MailOnline, over an article in August 2018 which reproduced parts of the handwritten letter sent to 76-year-old Thomas Markle.

There have been a number of preliminary hearings in the case so far, and a hearing to consider costs and case management issues was due to take place on Thursday, ahead of a 10-day trial due to start in January.

But instead of that hearing, Mr Justice Warby will now hear an application by the duchess for the trial to be put back to a later date.

According to a court document seen by the PA news agency, the application will be considered at an online hearing – the first part of which will be in private.

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 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 39-year-old duchess is seeking damages from ANL, the newspaper’s publisher and operator of the website, for alleged misuse of private information, copyright infringement and breach of the Data Protection Act.

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

Following the latest preliminary hearing last month, a judge ruled the publisher could rely on a recent biography of the Duke and Duchess of Sussex, called Finding Freedom, in its defence of the claim.

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 her father in August 2018.