Gary Goldsmith posted the message on LinkedIn whilst self-isolating after returning from holiday in Ibiza. It came after Prince Harry controversially claimed: “The world that we know has been created by white people for white people.”
The Prince made the comment whilst speaking to the Evening Standard to mark the start of Black History Month.
On LinkedIn Mr Goldsmith wrote: “With so much stuff going on in the world still these two muppets are craving attention!
“Please shut the F up and bring up your child. Stop talking and being so demanding!!
“Harry, you have lost our love and respect. Meghan you are a wrong’n.
“Now hush please we are kinda busy saving lives and the economy.”
Mr Goldsmith is the brother of Carole Middleton, Kate’s mother.
He attended Kate’s wedding to Prince William at Westminster Abbey in 2011.
Speaking to Mail Online Mr Goldsmith accused Meghan and Harry of “lecturing” the UK.
“We’ve all had enough of them lecturing us. You can’t sell your soul to Netflix for a reported £150 million and then dictate to Mother England.”
Harry and Meghan delivered their comments from their new £11.2million home to the north of Los Angeles.
The couple have made a number of politically charged interventions recently including Meghan calling for “change” in the upcoming presidential election.
During his Evening Standard interview Prince Harry said: “I wasn’t aware of so many of the issues and so many of the problems within the UK and also globally as well. I thought I did but I didn’t.
“You know, when you go in to a shop with your children and you only see white dolls, do you even think: ‘That’s weird, there is not a black doll there?’
“And I use that as just one example of where we as white people don’t always have the awareness of what it must be like for someone else of a different coloured skin, of a black skin, to be in the same situation as we are where the world that we know has been created by white people for white people.”
Harry and Meghan shocked the world in January by announcing they planned to step down as senior members of the Royal Family.
The couple said they would become “financially independent” and split their time between North America and Britain.
After a brief spell in Canada they moved to California shortly before the state went into coronavirus lockdown.
They recently signed a deal to produce films, documentaries and children’s shows for streaming giant Netflix.