'I am the Queen!': Elton John saw the Queen slap nephew in party feud

Queen Elizabeth II speaking with Sir Elton John backstage after the Diamond Jubilee concert at Buckingham Palace on June 4, 2012. Photo / Getty

Sir Elton John has claimed he once saw the Queen slap her nephew during a party, leaving the music icon stunned.

The 72-year-old said Princess Margaret's son Viscount Linley got into an argument with the Queen, prompting her to take action.

According to John's autobiography, the Queen turned to Linley and said: "Don't argue with me, I am the Queen!"

"I know the Queen's public image isn't exactly one of wild frivolity, but… in private, she could be hilarious.

"I saw her approach Viscount Linley and ask him to look in on his sister, who'd been taken ill and had retired to her room.

"When he repeatedly tried to fob her off, the Queen lightly slapped him across the face, saying, 'Don't' – SLAP – 'argue' – SLAP – 'with' – SLAP – 'me' – SLAP – 'I' – SLAP – 'am' – SLAP – 'THE QUEEN!'"

Apparently, the Queen's move worked with Linley scurrying away to fulfil the Queen's wishes.

When the Queen saw John staring, he wrote, "Her Majesty gave me a wink and walked off".

Linley is the son of the Queen's only sister and her husband Lord Snowdon.

Queen Elizabeth II smiles as she arrives at Tweedbank Station on September 9, 2015 in Tweedbank, Scotland. Photo / Getty

In the same excerpt of John's autobiography, John wrote about how Richard Gere and Sylvester Stallone almost got into a fistfight over Princess Diana after she'd separated from Prince Charles.

He also explained how he had a falling out with Diana before reconciling before her death.

He said the pair disagreed over a book of photographs that Diana was supposed to have written the forward for.

"Then she got cold feet. I think Buckingham Palace didn't like the idea of a member of the Royal Family having anything to do with a book that featured shots of naked guys with towels draped around them."

John said. "So, at the last moment, Diana withdrew her foreword. She said she had no idea of the book's contents, which just wasn't true: Gianni had shown her the whole thing and she had said she loved it.

"I wrote back to her, calling her out, telling her how much money she had cost the AIDS Foundation, reminding her that she had seen the book."

Elton John's biography Me will officially be published on October 15.