The Duke of York has not made any public appearances since Prince Philip's memorial at Westminster Abbey in March.
The Duke of Sussex said that being a working royal felt like he was "trapped in the system" like the rest of his family.
The British monarch turns 96 years old on April 21.
The Duke of York escorted Her Majesty to Prince Philip's memorial at Westminster Abbey on March 29.
The Duke of York surprised viewers when he walked Her Majesty to her seat during the service.
The image of Prince Andrew escorting the Queen is what people are talking about and not the Duke of Edinburgh.
The Prince of Wales told Her Majesty that he disapproves of the Duke of York being at Prince Philip's memorial.
The Duchess of Cambridge surprised viewers when she curtsied at the Queen while others did not.
The Duke of York divided opinions when he escorted Queen Elizabeth II to Prince Philip's memorial.
She sent out a "very complicated message" including that of shame or happiness at seeing Prince Andrew in public.
He "actually feels really down about not being able to attend this remarkable day in celebration of his grandfather."
Eyebrows raised and tongues wagged over the royal family's decision to give him a prominent role at Prince Philip's memorial.
The Duke of York was "front and centre" when he walked Queen Elizabeth II to her seat inside Westminster Abbey.
"It's a shame that something that was meant to be a celebration of his father has had a shadow cast over it."
The Duke of Sussex "does nothing but sit there feeding his chickens in California."
"It shows she wholeheartedly loves and believes her son."
"To put something as petty as security ahead of the obvious ethical, humane military and royal respect, it doesn't make sense, it's sad."
The Duke of Sussex announced that he will not attend Prince Philip's memorial at Westminster Abbey on March 29.
The British monarch "had the wherewithal to deal with his death."
The Duke of Edinburgh told Queen Elizabeth II that the couple's exit showed "a complete lack of respect."
The Duke of Cambridge refuses to invite his brother to his 40th birthday in June.
The Duke of York settled his sexual abuse case out of court with a reported amount of £12 million.
Senior aides plan to use "six-foot privacy screens or a football-style tunnel" to shield her from the photographers.
The monarch does not want to "risk all of that walking and sitting at the Commonwealth Day service in order to be able to go to Prince Philip's memorial."
"The Duke will not be returning to the UK in late March, but hopes to visit his grandmother as soon as possible."
The royals think it's unlikely "he'll come back because it would undermine his position that it's too much of a threat."
The wife of a king is always known as a queen, but the husband of a queen is usually not being styled as the king in England.
The 95-year-old, who marked her reign's 70th anniversary on Sunday, February 6, hosted a tea party at Sandringham on Saturday.
At the time of Prince Philip's death, it was being claimed that Andrew was using his father's death as an opportunity to return to his royal life.
The British monarch traditionally visits the estate this time of the year to mark the death anniversary of her father King George VI.