Prince William’s relationship with his brother Prince Harry has been strained since Meghan Markle accused Kate Middleton of making her cry ahead of her wedding, according to a royal expert.

The Mail on Sunday's assistant editor Kate Mancy claims that Meghan's false accusations against Kate have damaged the brothers' friendship.

Speaking to Palace Confidential on MailPlus, Ms Mancy said, “It was such a shame.

It was described to me as civil, which is Palace courtier for what the rest of us would refer to as frosty.

I do think those comments aimed at Kate were extremely damaging to the brothers' friendship.”

Meghan had previously accused Kate of reducing her to tears at Princess Charlotte's bridesmaid dress fitting, but the opposite is true, according to Harry's wife.

Meghan revealed that she has since forgiven Kate, but said it was really important for people to understand the truth.

“The narrative with Kate, which didn't happen, was really, really difficult and something that…I think that's when everything changed really,” she told Oprah Winfrey.

When Harry pressed Meghan, “So specifically, did you make Kate cry?”

Meghan replied, “No, no, the reverse happened.

And I don't say that to be disparaging to anyone, because it was a really hard week of the wedding, and she was upset about something, but she brought me flowers and a note apologizing, and she did what I would do if I knew that I'd hurt someone.”

Meanwhile, Angela Levin, a royal biographer, believes that Harry and Meghan crossed the red line in deciding to walk away from the monarchy.

“The Queen doesn't want the royal family's name to be tainted in that way and this, I think, crossed the red line,” she said.

“She's a very patient woman, she's not a micromanager.

She lets her children and grandchildren do what they want up to a certain extent and when they overstep that, she comes down.”

On Friday, Prince William and Kate Middleton appeared to give the cold shoulder to Prince Harry and Meghan Markle at a Thanksgiving service for the Queen's Jubilee at St. Paul's Cathedral.

According to People, as Prince William and Kate made their way to their seats, they passed Prince Harry and Meghan's pew but kept their eyes forward.

Prince Harry reportedly avoided looking at his brother directly, keeping his eyes forward as well.

The service marked the first time that the Cambridges and Sussexes were seen together at the same event since 2020's Commonwealth Day service, just days before Harry and Meghan stepped away from royal life.

Meghan and Harry arrived in the UK on Wednesday for the Queen's Jubilee, marking the first time they have returned as a family since Megxit.

While it has been reported that the Queen has already met them and their daughter Lilibet, the Duke and Duchess of Sussex are yet to be seen with the monarch.

The Queen pulled out of Friday's service after complaining of discomfort the day before.

The rift between the brothers has been growing since Meghan and Harry's departure from the royal family.

The couple's decision to walk away from the monarchy was a shock to many and has caused tension within the family.

The Queen has been patient with her grandchildren's decisions, but it seems that Meghan's accusations against Kate and the Sussexes' decision to leave the royal family have crossed a line.