Meghan Markle has been accused of mocking the Queen in a video message to launch her latest philanthropic campaign.

The Duchess of Sussex, who turned 40 on Wednesday, is joined by fellow American actress Melissa McCarthy in the two-minute video to launch a project through her and husband Prince Harry’s Archewell Foundation.

The video shows Meghan and McCarthy chatting back and forth, discussing ideas to celebrate the duchess’ milestone birthday.

An excited McCarthy quickly suggests a yacht party, and a tea party. Then she disappears off screen briefly, before returning in a gown – complete with pearls, gloves and a fascinator, and sipping tea from a bone china cup.

“This’ll probably seem better for you,” she tells Meghan.

Later in the video, a beaming Meghan joins McCarthy in enjoying tea from her own delicate cup.

“Cheers,” she says.

The exchange drew a rapid response from royal expert Angela Levin.

“Anyone else think that Meghan and her friend Melissa McCartney [sic] were mocking the Queen in the birthday video?” she tweeted.

“Both holding old-fashioned cup and saucer like Meg used in her blog after 1st meeting with Queen.

“Melissa sipping from the cup wearing fancy hat and gloves?”

Levin followed up with another tweet: “The mockery shows what she thinks of the Royal Family. She’s got what she wanted and is confident she can outsmart us all. We just have to wait for Harry’s outpouring in his memoir.”

Tweet from @angelalevin1

• Birthday video reveals offers first look at baby Lilibet

Levin is the author of the book Harry: A Biography of a Prince, and has spent years working as a journalist covering the royal family. She has covered countless royal engagements, including many with Prince Harry.

It’s not the first time she has criticised the Duke and Duchess of Sussex, particularly their recent criticism of Harry’s family.

Two weeks ago, she told Good Morning Britain that she was worried about Harry’s upcoming memoir.

“I don’t believe it’s going to be all honey and sweetness, I think he’s going to smash again,” she said.

“I don’t know why, does he want to destroy his family?”

The duke’s book – said to be an “intimate and heartfelt” account of his life from childhood to parenthood – is due to be published in late 2022.

It follows Harry and Meghan’s bombshell interview with Oprah Winfrey earlier in 2021, in which they accused the royal family of racism and failing to support the duchess when she struggled with her mental health during her first pregnancy.

“I think he will go as far as possibly can,” Levin said.

“I don’t think there are any more boundaries for him.”