Prince Harry “hates the idea” of completely losing touch with his friends, particularly with the decision of not attending the upcoming wedding of the Duke of Westminster who Harry was close to, claims a royal author.

Hugh Grosvenor, the 7th Duke of Westminster, is a close friend of both Harry and Prince William with his wedding due to take place next month on June 7.

Royal author and expert, Tom Quinn told the Mirror: “Harry hates the idea of completely losing touch with his old Etonian and army friends and he was close to Hugh Grosvenor, but attending a wedding at which his brother will be an usher is just history repeating itself in the most painful way.”

He added: “Harry felt he should have been invited to be an usher, but once again his brother takes precedence.”

It was previously reported that Harry turned down a “save the date” to Hugh’s wedding to Olivia Henson to avoid an “awkward” encounter with family members he is no longer on good terms with who are due to attend.

Speaking to Express.co.uk, a source claimed that by bringing William into the heart of the event, Prince Harry is said to have felt sidelined and so declined the invitation.

A source said: “William was asked to take up a leading role in the wedding and that’s what triggered Harry to decline an invitation. It was the final nail in the coffin.

“Harry was very close to Hugh growing up so everyone thought it would have been him taking up a leading role, not William.”

It was first revealed in December that Prince Harry was not attending the wedding, as Harry and Meghan both declined. It has been dubbed a ‘Royal wedding in all but name’, because of the high level of expected Royal attendance.

Despite Princess Kate still continuing with cancer treatment, her name has not yet been removed from the high-profile wedding scheduled next month, but a source warns her name remaining on the guest list does not guarantee her attendance.

A source told Express.co.uk: “William and Kate are both on the guest list and there has been no declining her invitation. But that might be because they have spoken informally. A lot is still up in the air with the Wales family.”

The guest list was put together last year, before Kate became aware she was ill, but the future Queen is often known to politely decline weddings, where possible, to avoid upstaging the bride. Aides say that, with Kate unwell, nothing in the Wales’s calendar is nailed on.

Hugh Grosvenor was long considered to be Britain’s most eligible bachelor and inherited his title and the Grosvenor Estate in 2016 after his father died. At only 33 years old, he is the richest person under 35 in the UK, worth £9.8 billion, according to The Times.