Charles Spencer accused King Charles of “gaslighting” him after Buckingham Palace challenged his account of an alleged conversation following Princess Diana’s death.

The dispute centred on claims in his forthcoming memoir, Swan Song: Diana, My Sister, that the then Prince of Wales told him: “We’ll forget her soon enough”, during a disagreement about Diana’s funeral arrangements.

Buckingham Palace responded with a statement suggesting that grief could affect judgment and recollection. Diana’s brother subsequently criticised that response as “astonishingly provocative and below the belt”.

Speaking to The Mail on Sunday, the earl said: “It is not every day you wake up to find you’ve been gaslit by the King.”

The exchange came ahead of the memoir’s publication on September 22, with extracts revisiting Diana’s life, her death and her sons’ experiences at her funeral.

Buckingham Palace’s response to Earl Spencer’s claims

The Palace issued its response on Wednesday after the earl’s allegations became public. A spokesman said: “While we do not comment on books as a matter of principle, His Majesty is mindful that the pain of fraternal grief can cloud reason, affect judgment and colour memory in ways others do not recognise, even many years after such a loss.”

The statement challenged the reliability of the earl’s recollections without directly addressing whether the alleged words had been spoken.

Charles strongly objected to that approach. “It was astonishingly provocative and below the belt because it was essentially trying to say I’d lied without the King being able to deny what I’d said,” he told The Mail on Sunday.

He also compared the statement with the late Queen’s response to Prince Harry and Meghan’s interview with Oprah Winfrey, which included the phrase “recollections may vary”.

“I also thought it was a rather poor imitation of the ‘recollections may vary’ quote, which was a much more elegant way of putting things, but in these circumstances entirely out of place,” he said.

Charles Spencer defended his account in a BBC interview

Charles also discussed the alleged conversation in a BBC interview with Laura Kuenssberg, an extract of which was released on Friday. The BBC report outlined his insistence that his account was accurate.

According to the earl, the disagreement concerned whether William and Harry should walk behind their mother’s coffin.

He alleged that the then Prince of Wales became angry and criticised the Spencer family’s sense of duty. “[The King] went ballistic, would be the right term, and started really going for my family as a whole, about their sense of duty, not being adequate enough, and ranted for a while, I have no idea how long, but it was a significant period, and I just listened,” he said.

He continued: “And then he stopped, and I thought, ‘Oh now he’s going to pull himself together and say something more appropriate’.

“And then he said, ‘We’ll forget her soon enough’.” Asked whether he had evidence of the alleged remark, Charles said he had shared his account with people close to him at the time.

“I told friends and family straight away, close friends and family, about what had been said, because it was so monstrous,” he said. He added: “I’m telling the truth.”

Charles Spencer recalled his concern for Prince Harry

In another extract from the memoir, serialised in the Daily Mail, Spencer described his concern for Harry on the day of Diana’s funeral.

The service took place on September 6, 1997. Harry was 12 and William was 15 when they walked behind their mother’s coffin alongside their father, their uncle and their grandfather, Prince Philip.

Charles recalled being struck by how young Harry looked, describing him as “tiny, and slight, and bereft”. He remembered thinking his nephew was “too small to be doing this”.

His account also covered the train journey from London to Althorp after the service.

“My chief memory of that train journey is of being concerned at the lack of obvious care for Harry, as he decompressed from the ghastliness of the morning,” he wrote.

“He needed Diana’s hugs, of course, and they would forever be denied him. “But instead of calm and nurture, he was allowed to spin out of control.”

What Earl Spencer’s new Diana memoir covers

Penguin confirmed that Swan Song: Diana, My Sister will be published on September 22.

The book traced the siblings’ childhood together, including the upheaval of their parents’ divorce, before exploring Diana’s marriage, motherhood, public work and the week of her death.

Its publication came nearly three decades after Spencer delivered his eulogy at Westminster Abbey, speaking about his sister before a worldwide audience.

Despite the dispute surrounding the extracts, he maintained that Diana would have supported his decision to publish his account. “Diana would be cheering from the rafters at this book,” he told The Mail on Sunday.