Prince William has decided not to invite Prince Harry to his 40th birthday on June 21 following the latter's decision not to attend Prince Philip's memorial on March 29.

The Duke of Cambridge was left shocked and appalled upon hearing that his brother will not fly out to the U.K. for the thanksgiving service for their grandfather, who died in April last year. A source said that the 37-year-old's decision has prompted William to change his mind about including him in his birthday celebrations.

The insider claimed that instead of waiting for Prince Harry and Meghan Markle to decline, Prince William would rather not invite them instead. "William still loves Harry – that will never change – but his apparent insensitivity makes him persona non grata at the moment and it will take some miracle for that to change," the source, who is said to be close to the older brother, told Heatworld.

The friend added that even if the Duke and Duchess of Sussex accept the invite, their presence at Prince William's birthday party may only create drama, which Prince William wants to avoid.

"The feeling is that, even if Harry and Meghan decided to come to William's celebration, and that is a big if, their presence would bring a whole fresh set of problems, and nobody wants that," the source added and claimed that the Duke of Cambridge sadly "barely recognises, let alone relates to, his younger brother anymore."

The last time the brothers reunited was at the unveiling of Princess Diana's statue at the Sunken Garden in Kensington Palace in July last year. That was the second time Prince Harry returned to the U.K. after Megxit. The first was for Prince Philip's funeral in April.

The brothers chatted and smiled during the unveiling and royal commentators claimed that they had put on a united front for the public. But it is said to be evident that their once-close bond is no longer there.

Prince Harry dropping out of Prince Philip's memorial on March 29 at Westminster Abbey is said to be due to concerns about his security in the U.K. He does not have his own police protection, but given that it is a family gathering, then expectations are that he will get the same security allotted to other royal family members during the said ceremony.

Meghan Markle, Prince Harry and Prince William
Prince Harry last year revealed that he had grown apart from his older brother William Photo: AFP / Tolga AKMEN