Royal historian, Dr Edward Owens, suggested Harry had fallen out of favour with the British public, and that his book was likely to be a bigger hit in the US, where the Duke of Sussex lives.
The former lecturer at the University of Lincoln and author of “The Family Firm” told Express.co.uk: “This is meant to be the Queen’s last hoorah, it’s very unlikely that there will be an 80th jubilee.
“Harry is hot right now, he’s interesting and he’s got to make what he can out of that interesting story whilst people are still interested in him.
“It’s being largely written for an American audience, he’s damaged goods in the UK.
“In the British public opinion polls, he’s really fallen from grace, the British public have very little time for Harry compared to pre the start of 2019.”
In October 2019, YouGov data showed Harry had an approval rating of around 71 percent with the British public.
But by January 2020, after Harry and his wife Meghan Markle had announced their intentions to quit the Firm, this rating had sunk to around 55 percent.
Meghan’s popularity in the same period also fell – from 55 percent to 38 percent.
Very few details have been released about Harry’s memoir, the proceeds of which are to be donated to charity.
Harry has said it will cover his family life, his childhood and his “dedication to service”, including his time with the military in Afghanistan.
Reports have suggested that the book may provide more details on his split from the Royal Family, although this has not been confirmed.
Harry and Meghan, 40, announced last year that they would step down from their royal duties.
The Duke and Duchess of Sussex have since carved out new roles for themselves in the US, including podcast and TV work.
Royal experts have also highlighted the timing of the memoir – released in the year the Queen celebrates her 70th year on the throne – as a potential source of friction with Buckingham Palace.
Dr Owens added: “At next year’s jubilee, the monarchy, the Queen and her advisers will be saying, ‘Don’t worry about it, that’s going on over the other side of the Atlantic Ocean, this is a celebration of Britain, the Commonwealth.’
“The date of publication becomes even more crucial because if it’s released prior to the actual jubilee, if there is incendiary, explosive material contained in the memoir, you almost think that Harry might not even get invited.
“I imagine Elizabeth will invite them next year to her platinum jubilee, whether Meghan accepts.
Prince Philip, the Queen’s husband and Harry’s grandfather, died in April of this year at the age of 99.
Harry flew from California, where he and Meghan live, into the UK for the funeral – his first trip back since the couple left the Royal Family.
Meghan, who was pregnant with their second child Lilibet Diana at the time, did not make the journey on the advice of her physician.
Source: EXPRESS CO UK