The brothers and their cousins will take part in the special 15-minute vigil at Westminster Hall on Saturday, where they will stand beside the Queen's coffin in silence, mirroring the Vigil of the Princes.
The Vigil of the Princes saw King Charles, Princess Anne, Prince Andrew and Prince Edward stand guard at St Giles' Cathedral in Edinburgh earlier this week. They will repeat the vigil at Westminster Hall on Friday night.
Prince Andrew has controversially been allowed to wear his military uniform for the Westminster Hall vigil despite stepping back from royal duties in the wake of his friendship with Jeffrey Epstein and the sexual assault allegations that followed.
Harry, however, was not granted the same exception for events in the lead-up to the Queen's funeral, with a spokesperson hitting back, "Prince Harry, The Duke of Sussex will wear a morning suit throughout events honouring his grandmother.
"His decade of military service is not determined by the uniform he wears and we respectfully ask that focus remain on the life and legacy of Her Majesty Queen Elizabeth II."
Now that Harry will be allowed to wear his uniform for the special vigil, a source told The Mirror, "Common sense has prevailed.
"It was a ludicrous situation given the Duke of Sussex has served his country and is a highly respected member of the armed forces with everything he has done for veterans.
"It is important that the Queen’s grandchildren are all made to feel welcome and comfortable as they grieve their beloved grandmother together."
Harry, who served in the British army for a decade, including two tours of Afghanistan, was stripped of his military patronages when he and wife Meghan Markle stepped back as working royals.
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