Prince Harry may have to rethink his future with the British royal family when Queen Elizabeth II dies, according to a royal biographer.

Speaking on BBC Radio 4's "Today," Tina Brown thinks that the 37-year old will want to return to the U.K. and resume his royal duties when his grandmother passes away. She believes that "there'll be a kind of desire for Harry to serve his country."

"I think he's going to want to rethink it. Frankly, I don't think the entertainment efforts are going that brilliantly, sitting in Montecito," she said referencing the Duke and Duchess of Sussex's deals with Netflix and Spotify.

The streaming giant recently cancelled "Pearl," the animated series the former "Suits" star was set to executive produce along with David Furnish as director. It was still in its early stages of development under Archewell Productions. As far as other announced projects with Netflix go, the couple only has the Invictus Games documentary, "Heart of Invictus," to work on.

Brown added that the royals will also want to put in an effort to bring Prince Harry and Meghan Markle "back in a certain point, not for a bit." She guessed that the couple "will want to come back, eventually."

"Right now it's not going to happen, largely because Harry keeps lobbing these fresh hand grenades at the family, just when they are beginning to think, 'Well, can we re-establish some trust with the House of Sussex?,'" she explained in reference to the duke's recent statement about him wanting to ensure the Queen's safety.

The author of "The Palace Papers: Inside the House of Windsor, the Truth and the Turmoil" said his comments about wanting to make sure Queen Elizabeth II has got the right people around her sparked a protest from the royals. She claimed, "A lot of people in the [royal] family thought, 'Actually, she needs protecting from you, Harry.'"

In a previous interview, Brown also claimed that it was Prince Harry who was eager to leave his royal life behind. Meghan Markle only helped him speed up the process because she has connections in the entertainment business.

Meghan Markle, Prince Harry, Queen Elizabeth II
"Harry, Meghan and Archie will always be much loved family members," Queen Elizabeth stressed in her statement Photo: POOL / John Stillwell