The former Good Morning Britain presenter's rant – in which he dubs the Duke and Duchess of Sussex "Prince Poison and Princess Pinocchio" – comes in reaction to news that Harry is to publish a tell-all memoir next year.
Morgan wrote in his column in the MailOnline: "I've said this before, and I now say it again: the Queen should strip Harry and Meghan of all their titles with immediate effect.
"Compel them to do this malevolent, manipulative cr*p in their names, not as royals."
Watch: Harry to publish 'wholly truthful' book on his life in 2022
Harry and Meghan resigned from their royal duties in January 2020 and after moving to the US have signed up to a number of lucrative deals with Netflix, Spotify and now Penguin Random House, but they formally remain the Duke and Duchess of Sussex.
The news that Prince Harry is to publish an "intimate and heartfelt" autobiography about his life, "not as the prince I was born but as the man I have begun", has sparked heated speculation as to what secrets he will reveal about the Royal Family and how they will feel about the book.
Morgan fumed: "To be blunt: Harry's a sell-out, and this is just another example of him selling out.
"It's sad, pathetic, and totally unnecessary, and it will obviously cause yet more pain to his grandmother who is still mourning the loss of her husband Philip."
And he added: "Prince Poison has gone toxically rogue, and the royals should have nothing more to do with him or his wife Princess Pinocchio until or if they stop this horribly destructive vituperative rampage against them all.
"The memoirs are a slap in the face too far for a family that's surely exhausted all collective patience with the Sussexes."
Morgan, 56, quit ITV breakfast show GMB in March over comments he made about Meghan's interview with Oprah Winfrey.
Former actor Meghan, 39, married Prince Harry in 2018. They have a two-year-old son Archie and welcomed daughter Lilibet on 4 June this year, naming her after the Queen's childhood nickname.
Watch: What are Prince Harry and Meghan's plans for Lilibet's christening