The Court of Appeal will give its ruling on the latest stage of a legal battle between the Duchess of Sussex and the publisher of The Mail On Sunday over a letter to her estranged father.
The duchess, 40, sued Associated Newspapers Limited (ANL), also the publisher of MailOnline, over five articles that reproduced parts of a "personal and private" letter to Thomas Markle, 77, in August 2018.
The duchess won her case earlier this year when a High Court judge ruled in her favour without a full trial.
However, ANL brought an appeal and, at a three-day hearing in November, argued the case should go to a trial on Meghan's claims against the publisher - including breach of privacy and copyright.
Three senior judges will give their decision on the appeal at 10am on Thursday.
Judges Sir Geoffrey Vos, Dame Victoria Sharp and Lord Justice Bean were told that 585 out of 1,250 words had been republished in the five articles.
Meghan's barristers argued that the letter was "deeply personal" and "self-evidently was intended to be kept private".
In her written evidence, Meghan denied she thought it likely that her father would leak the letter, but "merely recognised that this was a possibility".
Jason Knauf, former communications secretary to the Duke and Duchess of Sussex, claimed in a witness statement that Meghan wrote the letter with the understanding that it could be leaked.
He said she sent him an early draft of the letter and had written: "Obviously everything I have drafted is with the understanding that it could be leaked so I have been meticulous in my word choice, but please do let me know if anything stands out for you as a liability."
In further texts released by the court, the duchess can be seen expressing her frustration about the response of the royal family, describing them as "constantly berating" Harry.
The Court of Appeal also heard that Mr Knauf provided information to the authors of the biography Finding Freedom - Omid Scobie and Carolyn Durand - leading to Meghan apologising for forgetting about e-mails she had sent to Mr Knauf when she gave her original evidence to the court.