British commentator Piers Morgan says he will sue Charles Spencer and his publishers over “bulls..t” claims the brother of Princess Diana made about him in his new memoir.

Spencer’s 384-page memoir, Swan Song: Diana, My Sister is due to go on sale internationally on Tuesday.

In a statement posted to X, Morgan said he had instructed lawyers to pursue legal action against Spencer and publisher Penguin Random House, demanding the removal of passages he says contain “demonstrable lies” about him.

“I am taking legal action against Earl Spencer and his publishers over demonstrable lies he has written about me in his new book, which call into question his credibility as a supposed ‘historian’. Full details to follow on tonight’s Piers Uncensored,” he wrote.

Morgan later addressed the move in more detail on his program, Piers Morgan Uncensored, telling viewers a segment of the book falsely implicates him in the publication of intrusive photographs of Diana exercising at a gym in 1993.

“Earl Spencer’s book contains fabricated inaccuracies which will strike to the heart of his credibility,” Morgan told his viewers.

“His book is out tomorrow, I’ll expect maybe many more examples of brazen falsity after what I’ve uncovered about purely an entry about myself.

“Pretty extraordinary stuff, isn’t it? And very damning, particularly about me.

“I come across in the most despicable manner imaginable. There’s just one problem. It’s all bulls..t, and very, very easy bulls..t for me to prove it.”

He said his dispute centres on photographs published by the Sunday Mirror on November 7, 1993. Spencer writes that Morgan and his Sunday Mirror counterpart published the images, which had been taken using hidden cameras by the gym’s owners.

But Morgan said Spencer’s account is incorrect because he did not join the Daily Mirror until almost two years later.

“I joined the Daily Mirror in October 1995. In fact, at the time of the gym pictures, I was doing a showbiz column on the Mirror’s arch-rival, The Sun,” Morgan said to the camera.

“About as far removed from responsibility for the Mirror scoop as I could possibly have been.

“I’m not claiming to be a journalistic angel, but on this particular thing that he says about me, he’s 100% wrong.”

The editor of The Mirror when the photographs were published was David Banks, Morgan said.

In the book, Spencer also recounts calling newspaper editors before Diana’s funeral in 1997 to withdraw their invitations. He described Morgan as as responding “surly” before hanging up, then link his reaction to the controversy over the gym photos.

Morgan reiterated his decision to pursue legal action and demanded the passages be removed from the memoir.

“In the meantime, Earl Spencer, you’ll be hearing, and your publishers from my lawyers because I would like the complete lie that you’ve published about me and those photographs to be removed from your book.,” he added.

“And I would like a donation to be made to the King’s Trust for the damage you’ve caused with your lie”.