Prince Andrew has "never got over" once being second in the line of succession an aide has claimed, amid his ban from certain royal events.
The Duke of York stepped down from royal duties in the wake of a sex scandal earlier this year.
He denied the allegations against him and later came to an out of court settlement with his accuser. The settlement is not an admission of guilt.
He was forced to remain out of sight during the Garter Day procession on Monday after a "family decision" was taken to limit his appearance to a behind-the-scenes lunch and investiture ceremony.
As Prince Charles, Prince William and other senior royals went through the grounds of Windsor Castle for a church service commemorating the Order of the Garter, Andrew stayed behind closed doors.
Meanwhile, a report at the weekend claimed that Andrew finds his HRH status important and is keen for his 'Prince of the Blood' recognition to be returned in order to attend official events with members of the Royal Family.
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When Andrew was born, he was second in line to the throne behind his older brother Charles but over time, he has now slipped to ninth.
And an aide told the Daily Mail's Richard Kay: "The problem with Andrew is that he has never got over the fact that he was once second in the line of succession. And now he’s not."
Meanwhile, another royal expert has claimed that Andrew was "crushed and confused" at being barred from Garter Day having thought he had been given the green light to attend
Finding Freedom author Omid Scobie also said that the royals’ “reluctance to completely remove Prince Andrew” is damaging and “reflects terribly on the family”.
He claimed, in his Yahoo News column, that the Duke of York was “crushed… (and) a little confused.”
He said that the way Andrew was allowed to walk with the Queen at Prince Philip ’s memorial service, as well as attend some of the Jubilee events, shows the reluctance of the royals to cut him off entirely.
Mr Scobie said: “Every chance Prince Andrew is given to try and rehabilitate his image is a step closer to further damage and shame for the institution of the monarchy. It’s a disaster waiting to happen.”