There will also be an absence of some high-profile royals, most notably Prince Harry, the Duchess of Sussex Meghan Markle, and Andrew Mountbatten-Windsor and his family, following his fall from grace
But as preparations get underway for next week's 'low key' royal wedding, dark clouds are hanging over it linked to Ms Sperling's previous marriage to fitness instructor Antonio St John Sperling, 44, who is known as Dino.
A source told the Daily Mail: 'He's not very happy about how he's been portrayed by Harriet and feels that he's been completely written out of the narrative by her.
She's spoken in the past about struggling as a single mother, but Dino has tried to hold out the olive branch many times over the past few years to her and her family. But they've rejected any of his offers for help.'
The source added: 'Harriet has landed in the big time. She's marrying into the Royal Family and will never have to worry about money or paying a bill ever again. It's not been like that for Dino, he's struggled for a long time both financially and emotionally. He's being made out to the bad guy by her and that's simply not true.