Royal commentator Kinsey Schofield told GB News that Prince Harry is "immature" and needs to "grow up" after choosing to launch a new attack on the Royal Family just hours before Kate's birthday.
In an interview aired last night, the Duke of Sussex made a series of allegations about the conduct of the Royal Family and detailed rows between Kate and his wife, Meghan.
She said: "Can we just acknowledge he is doing this all on Catherine’s birthday, the Princess of Wales.
"They are just so shameless."
Schofield added: "This guy is so immature, when is he going to grow up?
"He is almost 40-year-old and he is complaining about tiaras and titles, whilst we are dealing with inflation, recessions, strikes, and immigration issues, in both of our countries (UK and US).
"No one can relate to these conversations."
Prince Harry's details an argument between Meghan and Kate in his autobiography Kirsty O'Connor
The Duchess of Cambridge is celebrating her 41st birthday today.
On Sunday evening, during Prince Harry's bombshell interview with ITV's Tom Bradby, the Duke's description of crisis talks between Meghan and Kate was highlighted.
Mr Bradby says regarding the extract in Spare: "At one stage, Harry recounts a clear-the-air meeting involving him, William, Kate, and Meghan.
"It seems to have gone so badly wrong that he describes Kate as gripping the edges of the leather chair so tightly that her fingers were white.
"Kate says she's owed an apology from Meghan who previously put a moment of Kate’s forgetfulness down to so-called baby brain.
"According to Harry, Kate tells Meghan they're not close enough to talk that way and William says, ‘That’s not what's done here in Britain’.
"The meeting ends awkwardly, with a hug of sorts."
Prince Harry also outlined his disappointment at the Palace for not correcting the story that Meghan made Kate cry during the run-up to the Sussexes' wedding in 2018.
Harry reiterated the claim Meghan made during her 2021 interview with Oprah Winfrey, that it was Kate who had made Meghan cry days before the royal wedding.
Meghan told Oprah regarding the argument: "A few days before the wedding, she was upset about something pertaining to ... flower girl dresses.
"And it made me cry."
Meghan claimed Kate made her cry just days before her wedding to Prince Harry in 2018 Netflix
"And it really hurt my feelings, and I thought in the context of everything else that was going on in those days leading to the wedding, it didn't make sense to not be just doing whatever everyone else is doing, which was trying to be supportive knowing what was going on with my dad and whatnot."
Regarding giving further details of the argument, the Duchess of Sussex added: "I don't think it's fair to her to get into the details of that, because she apologised. And I've forgiven her.
"What was hard to get over was being blamed for something that not only I didn't do, but that happened to me.
"I would have never wanted that to come out about her ever, even though it had happened."