After Harry and Meghan were slammed for using a private jet during a trip to France, fashion stylist Mulroney, who has remained silent until now, tookto Instagram to lash out at the "racist" critics.
She began her rebuke by sharing a tweet from British actress Jameela Jamil, who accused English citizens and the media for coming after the Duke and Duchess of Sussex because of Meghan's race.
Meghan Markle's best friend Jessica Mulroney has come to her defence. Photo / Getty Images
"Ugh. Dear England and English press, just say you hate her because she's black, and him for marrying a black woman," read Jamil's tweet.
"Your bullying is so embarrassing and obvious. You've all lost your marbles. It's 2019. Grow up."
Jamil also defended Harry and Meghan's decision to use a private jet - explaining it's essential for their protection.
The Canadian stylist reportedly helped the Duchess plan her royal wedding, and all three of Mulroney's children served as bridal attendants on Meghan's big day. Photo / Getty Images
"They are prime targets for kidnap and sometimes assassination," she wrote.
"It's in the interest of us civilians to not be endangered by proximity to people in such powerful positions."
Later that day Mulroney also took to Instagram to address the "unfair criticism" of her friend.
"When someone faces unfair criticism, you call it out. When that person is your friend and your family, you call those critics what they truly are," she wrote.
"Shame on you, you racist bullies. 3 years of undeserved hate and abuse. It's enough."
This week multiple famous friends of the Duke and Duchess of Sussex have rallied to their defence following accusations of hypocrisy over their use of private jets, saying the couple are just "trying to make the world better".
Portia and I met Prince Harry and Meghan in England to talk about their work on wildlife conservation. They were the most down-to-earth, compassionate people. Imagine being attacked for everything you do, when all you’re trying to do is make the world better. pic.twitter.com/226pRO1fj1
I’m happy to see people coming to the defense of The Duke and Duchess of Sussex. The way people treat her is the most public form of bullying I have seen in a while. It’s out of control. Let’s all be a bit kinder, huh? Let’s show our children that it’s cool to be kind.
American talk show host Ellen Degeneres, who has recently visited the Duke and Duchess, and pop star Pink both issued statements lamenting the "public form of bullying" endured by the couple, after details of their holidays to Ibiza and Nice emerged.
It is the latest of the high-profile support for the Duke and Duchess, whose circle of celebrity friends are increasingly using interviews and social media to act as unofficial spokespeople to protect the couple from what they view as "attacks".
On Monday, Sir Elton John claimed the Duke and Duchess had been subject to "relentless and untrue assassinations" after being photographed with their baby son Archie Mountbatten-Windsor boarding a private jet to his home in the south of France.
