Queen will appoint UK prime minister from Balmoral Castle, not Buckingham Palace, in historic first due to mobility issues

In a historic first, Queen Elizabeth will reportedly appoint the new British prime minister from Balmoral Castle instead of Buckingham Palace.

Her Majesty, 96, is suffering from mobility issues and has been advised to scale back travel, which will mean she is expected to stay in her Scottish Highlands residence for the appointment of either Liz Truss or Rishi Sunak on September 6.

The change in location will mean the new prime minister will be required to make the journey to Scotland for the ceremony in order to seal the transition of power.

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Due to her mobility issues, the Queen, who is currently enjoying her annual summer holiday at Balmoral, will no longer be expected to travel to London for the event when Boris Johnson officially resigns on September 5.

This will reportedly mark the first time the ceremony has taken place outside of Windsor Castle or Buckingham Palace.

An official decision will be made and announced publicly soon, because the outgoing and incoming prime ministers will need as much notice as possible.

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A source from The Sun touched on the decision for the monarch to stay put, saying, "It may not be the best choice to make the Queen travel 1,000 miles (1,609 kilometres) there and back for a 48-hour visit when the Prime Ministers can easily get to Balmoral instead."

The move has sparked fresh health concerns for Her Majesty, who was reportedly initially expected to make the journey to Buckingham Palace to meet with Johnson and his incoming successor.

Queen Elizabeth has pulled out of a number of events in recent months.

At 96, she is growing increasingly frail, and has this year already had COVID-19, with the palace confirming her diagnosis in February.

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She later said the virus left her feeling "very tired and exhausted".

Her Majesty also missed appearances throughout her Platinum Jubilee celebrations.

A number of adjustments have been made in recent years to accommodate the Queen's age, including having the Imperial State Crown carried into parliament and placed on a cushion next to her.