Meghan Markle and Prince Harry 'damaged' by disastrous end to 2023

He explained: "The Hollywood Reporter article on them was pretty damaging to their prestige.

"To be listed as one of the most prominent losers in the showbiz industry of 2023 will have done them no favours in terms of generating interest or support or of course, donations to Archewell. All of that is linked to the celebrity world."

WATCH NOW: Harry & Meghan's 'star power fading' after Endgame discussed by royal commentator

Royal author Omid Scobie released his royal book Endgame last month, which generated several stories about rifts in the Royal Family.

Harry and Meghan have not commented on any of the claims in Endgame, and Scobie has always maintained that the couple were not involved in the writing process.

Russell believes that this book "came at quite a bad time" for the Sussexes.

He explained: "Endgame came at quite a bad time for them. I think it would have been in their better interests to shift away from the narrative.

"Because the only time you really see them prominently in the headlines is when they are they have directly or indirectly attacked the Royal Family.

"It's clear it's not working in terms of generating public sympathy.

"But there was a great deal of public sympathy for them and an enormous amount of public interest. And that isn't quite there."

The royal commentator, who previously wrote The Palace: From the Tudors to the Windsors, 500 Years of Royal History at Hampton Court, explained what the Sussexes could do to restore their reputation after Endgame.

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Russell opined: "I would imagine, perhaps, more of a pivot towards the charitable events that Prince Harry has done so well, and those the Duchess of Sussex has expressed an interest in. It has to look less about them.

"The Sussexes' critics have said that the majority of their attention seems to be on rebutting stories like whether or not they were invited to the Duke of Westminster's wedding, rather than engaging in more positive stories.

"So I would imagine if the Sussexes return to their charities with the focus they've shown before and to other projects, 2024 could be a year where they help turn around some of the public opinion for them.

"But I do think it has to be a different tactic going forward than what we've seen in 2020, 2021, 2022 and 2023."