The Queen gave Prince Harry and Meghan permission to name their daughter after her, but thought she would be called Elizabeth, it has been claimed.
The monarch is said to have had a phone call with her grandson in which he told her of the couple's intention, but she was reportedly taken aback when her granddaughter was called Lilibet.
That was a nickname given to her as a child and one which late husband Prince Philip used as a pet name for her.
Interior designer to the royals Nicky Haslam made the claim on a podcast and insisted the Sussexes should have called their second born Doria instead.
He said he had been told the Queen had found the idea of naming the now one-year-old after "charming" but was "thinking it would be Elizabeth".
"So they got the permission, but they didn’t say the name."
Speaking on The Third Act podcast, the 82-year-old socialite who counts Camila, as well as Prince Michael of Kent as friends, went on to question why the little royal wasn't named after Meghan's mum Doria Ragland.
"Why on earth didn’t they call that baby Doria?" he asked, adding: "It’s the prettiest name ever."
Last year, BBC royal correspondent Jonny Dymond claimed the Sussexes had never asked the Queen for permission to use her pet name.
In response, the couple launched an unprecedented legal attack on the broadcaster, saying the story was "false and defamatory".
Their spokesman said at the time: "The Duke spoke with his family in advance of the announcement — in fact, his grandmother was the first family member he called.
"During that conversation, he shared their hope of naming their daughter Lilibet in her honour.
"Had she not been supportive, they would not have used the name."
It comes after royal sources reportedly claimed Prince Charles had a "very emotional" first meeting with granddaughter Lilibet and reunion with grandson Archie during the Platinum Jubilee.
Harry and Meghan, as well as their two children, made the trip to the UK for the Queen's landmark celebrations last month.
The pair were seen at the windows of Buckingham Palace during the parade but did not join the rest of the Firm on the balcony for the Red Arrows flypast.
And later attended a service at St Paul's Cathedral, but were kept away from senior royals, including Harry's brother Prince William.
It was just the second time Harry and Meghan had been seen together in the UK since stepping down as working royals in March 2020.
They had also made a brief stop off at Windsor on their to the Invictus Games in Holland in April.