Thomas Markle Sr. had wanted to participate in the Platinum Jubilee celebrations because he allegedly had an ulterior motive. According to a royal biographer, he had wanted to give Meghan Markle an ultimatum and have cameras around to capture him doing so.

Author Tom Bower said that he has been in touch with the 77-year old "for some time" because of the book he wrote about the Duchess of Sussex which is due to come out this year. He said that the former Hollywood lighting director is "very upset" and "very unhappy" at how his daughter is treating him after everything he had done for her.

The biographer talked about Thomas Sr. having to pay for Meghan Markle to go to a prestigious university. He was also there for her when her mother Doria Ragland was not around.

"He was a very loving father to Meghan and supported her throughout her childhood when her mother wasn't there," Bower said in an interview on "Good Morning Britain."

The author then revealed that Thomas Sr.'s plan to go to the U.K. for the Platinum Jubilee celebrations was partly because of his estranged daughter. He wanted to see her and possibly also meet his grandchildren, Archie, 3, and Lilibet, 11 months.

However, Bower claimed that Meghan Markle's father had planned to have cameras tailing him at the event. When asked how he could possibly see the children when he could just be another "face in the crowd," the author revealed, "Well no, he was going to come to Windsor with TV cameras and he was going to issue an ultimatum that Meghan should come out of Windsor Castle and see him and bring the grandchildren too."

Bower's revelation comes following news that Thomas Sr. suffered a major stroke on Monday evening. He is now recovering in a hospital. This means he may not be able to join the Platinum Jubilee celebrations in June. He had initially expressed his wish to meet Prince Charles so he could personally thank him for walking Meghan Markle down the aisle at the Royal Wedding in 2018. He had also said he wanted to see Queen Elizabeth II.

Prince Harry and Meghan Markle
Prince Charles, Camilla Parker-Bowles, Queen Elizabeth, Meghan Markle and Prince Harry at the Jubilee. Photo by: Getty Images/Tolga Akmen Getty Images/Tolga Akmen