The Duke of Sussex is scheduled to make a High Court appearance on the same day his brother, the Prince of Wales, will be 120 miles away on royal engagements.
Prince Harry, 41, is expected to return to London next week as the trial against the publisher of The Daily Mail begins.
The Duke and a group of six other high-profile names are bringing the claim at the High Court, alleging that Associated Newspapers Limited (ANL) carried out or commissioned unlawful activities such as hiring private investigators to place listening devices inside cars, "blagging" private records and accessing private phone conversations. ANL vehemently denies the allegations.
According to a draft trial timetable seen by The Press Association, Harry is expected to give evidence lasting a full day next Thursday.
On the same day, the Prince of Wales, 43, will travel to Bristol to showcasing the city's trailblazing achievements in sustainability and its role as a driving force for innovation in the UK.
While Harry was reunited with his father, the King, at a Clarence House meeting last September, his relationship with his older brother, William, is still believed to be estranged.
The relationship soured further when the Sussexes made a number of claims against the royal family in their 2020 interview with Oprah Winfrey, and in his memoir, Spare, released in January 2023, Harry detailed an alleged physical fight between himself and William.
The royal brothers were last publicly pictured together, seated three rows apart, at the King's coronation at Westminster Abbey in May 2023. While they were last in the same room at their maternal uncle Lord Robert Fellowes' funeral in Norfolk in August 2024, they reportedly did not speak or sit next to one another.
Harry is not expected to meet with any of his family members during his return to the UK next week. The King and Queen are expected to remain at Balmoral in Scotland for the rest of the month.
The Prince and Princess of Wales will also visit the city of Stirling in Scotland on Tuesday, where they will meet the Team GB and Paralympic GB curling squads at the National Curling Academy ahead of the Winter Olympic and Paralympic Games.