Prince Harry has had a significant victory in his battle with Buckingham Palace over his role in the Queen’s funeral commemorations.

The Duke of Sussex’s win comes ahead of another historic step by the Queen’s grandchildren.

Harry has reportedly been given special permission to wear his military uniform when he joins his cousins and the other senior royals at a lying-in-state vigil for the late monarch at Westminster Hall this weekend.

He had been banned from wearing his uniform because he and wife Meghan Markle are no longer working royals. The ban also extended to Harry’s uncle, Prince Andrew – although the Duke of York was given special permission to don a uniform for the historic “vigil of the princes” as the Queen’s coffin lay in state in Edinburgh earlier this week.

Harry and Andrew, the only senior royals to have actually seen active military duty, were conspicuous in their morning suits when they joined the King and his siblings in a procession behind the Queen’s coffin to Westminster Hall on Wednesday.

But, according to reports in Britain’s Mirror newspaper on Friday, there has been a change of heart at Buckingham Palace.

“Common sense has prevailed,” a royal source told the paper.

“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.”

Princess Anne joined her brothers – the King, Andrew and Prince Edward – in a historic moment for the vigil of the princes in Edinburgh. It was the first time a princess had taken part in the vigil around a sovereign’s coffin.

The scene will be repeated in London on Saturday (Australian time).

That night, there will be another historic moment when eight of the Queen’s grandchildren – including Harry and his brother, heir-to-the-throne Prince William – mount their own vigil.

The Queen’s other grandchildren, including Andrew’s daughters Princesses Beatrice and Eugenie, and Anne’s children Zara Tindall and Peter Philips are also understood to be planning to form part of a guard of honour on Saturday night. Her youngest grandchildren, Prince Edward’s 14-year-old son James, Viscount Severn, and 18-year-old daughter Lady Louise will also be involved.

Prince Harry spent a decade in the British army, including two tours of Afghanistan. He lost his honorary military titles, along with his HRH styling, when he and the Duchess of Sussex quit as working royals for a move to North America in March 2020.

Harry confirmed earlier this week that he “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,” a spokesperson said.

Andrew, the Duke of York, served in the Royal Navy during the Falklands War. He has also been stripped of his royal roles, and HRH title, following his multimillion-pound settlement in a sexual abuse civil lawsuit.

Mourners from all walks of life have queued to file past the coffin of the Queen as she lay in state in London’s Westminster Hall.

People are waiting hours in line, with the queue stretching up to seven kilometres along the south bank of the River Thames. Up to a million people are expected to view the coffin ahead of the monarch’s state funeral on Monday.

Also on Friday, the King and Queen will travel to Wales. The trip will mark the end of a tour of the United Kingdom where the King has performed ceremonial duties to acknowledge his status as the new monarch and head of state, and to greet the public mourning the loss of Elizabeth, who reigned for 70 years.

The royal couple will be greeted with a 21-gun salute, attend a cathedral service, and travel to the Welsh parliament.

The new Prince of Wales, William, will visit troops from Australia, New Zealand and Canada, who are in Britain for events surrounding Monday’s state funeral. Prince William will be accompanied by wife Kate, the new Princess of Wales.

-with AAP