A source told The Sun that the Queen was growing “exasperated with repeated attacks”.
They said: “The feeling, coming right from the top, is that enough is enough.
“There is a limit to how much will be accepted and the Queen and Royal Family can only be pushed so far.
“They are getting lawyered up. Harry and Meghan will be made aware and know repeated attacks will not be tolerated.
“The royals’ legal team are speaking to firms with expertise in libel and privacy.
“If someone were named in the book and accused of something directly that could be a libel and also infringe their rights to a private family life.
“It would be ironic if Harry and Meghan were accused of breaching privacy given their pronouncements on the subject.
“The legal team could also contact publishers of the book to ask for advance warning of its contents and a right to reply.
Earlier this week, Omid Scobie, one of the authors behind Meghan and Harry’s unauthorised biography Finding Freedom, claimed that the royals and the Sussexes have not made much progress with improving relations.
In an interview with PEOPLE magazine, he said: “In terms of Harry’ relationship with his father and brother, that progress has been very little.
“I think he is quite willing to own his part in everything, but I have been told that he is also waiting to see some of that on the other side – and as of now there hasn’t been that.”
Mr Scobie made the comments as he and fellow writer Carolyn Durand are preparing to release the paperback version of Finding Freedom that includes a new epilogue.
The release date will be on August 31, which will coincide with the anniversary of Princess Diana’s death.
An extract from the updated book was also published in this week’s PEOPLE magazine, which claimed Harry and Meghan have “no regrets” about leaving the Royal Family.
A friend of Harry’s told the authors that Harry’s brief reunion with the royals for Prince Philip’s funeral in April only briefly helped with relations.
They said: “While there’s so much work to be done, this visit has broken the ice… pushed a close door slightly ajar.”
Last month, publisher of the book HarperCollins said the epilogue in the paperback edition will share “behind the scenes of Harry and Meghan’s groundbreaking interview with Oprah, details behind the couple’s move to California (and) the various philanthropic and business endeavours the Sussexes have been involved with since their move and what’s to come with Archewell Productions.”
It will also include “the continuous challenges the couple face regarding privacy and the British press (and) the heartbreak the couple felt over Prince Philip’s death.”
Meanwhile, Harry’s new memoir is set to include the break-up of his parents Prince Charles and Princess Diana’s marriage, as well as the period of Diana’s death in 1997 and its aftermath. Harry’s relationship with stepmother Camilla and past girlfriends are also likely to form part of the book.
Harry said in a statement about his book: “I’m writing this not as the prince I was born but as the man I have become.
The prince has also hit the headlines around the world this year as he and Meghan shared in shocking detail their reasons for quitting the Royal Family last year.
During their Oprah interview in March, Harry also spoke about feeling “trapped” within the Firm.
He said: “My father and my brother, they are trapped. They don’t get to leave. And I have huge compassion for that.”
Harry then added that “there’s a lot of hurt that’s happened” between them, while Meghan claimed she did not receive support from the monarchy when she felt suicidal as a royal.
Buckingham Palace responded: “Recollections may vary.”
Express.co.uk has contacted both Buckingham Palace and a spokesperson for the Duke and Duchess of Sussex for a comment.
Source: EXPRESS CO UK