The royal family, as well as their staff and guests, were living with temperatures set at 19C during the winter.

Rooms were kept at 16C when empty according to the accounts of the Sovereign Grant, which is funded by the taxpayer.

Net expenditure increased by £5.1m, or 5%, to £107.5m for 2022-23, which royal aides said was due to the change of monarchs, inflation and the continued costs of Buckingham Palace's reservicing programme - the 10-year project to update the electrical cabling, plumbing and heating.

The Sovereign Grant, meanwhile, remained unchanged at £86.3m during 2022-23, while income to supplement the grant, through rents collected from royal properties and recharges to the Royal Collection Trust, dipped 1% to £9.8 million.

It meant that £20.7m was used from the Sovereign Grant's reserves - effectively savings set aside to cover gaps in funding.

Funding of the King's official duties and his household costs £51.8m - equivalent to 77p per person in the UK - while £34.5m pays for ongoing reservicing costs for the palace.

Payroll costs were one of the biggest annual increases of any expenditure during 2022-23, rising £3.4m to £27.1m, with staff given a pay rise of about 5% to 6%.

The number of staff also increased to pre-pandemic levels as royal activities picked up after the lockdowns.

But the royal household failed to meet its diversity target of drawing 10% of its workforce from ethnic minorities, with the 2023 figure of 9.7% the same as last year.

The cost of royal travel was down by £600,000 to £3.9m. Spending on 179 helicopter flights topped £1m.

The most expensive trip was the King and Queen's visit to Rwanda in June last year, and a separate staff planning visit, to attend a Commonwealth leaders' summit, costing £186,571.

A Buckingham Palace spokesperson also confirmed that the Duke and Duchess of Sussex had moved out of Frogmore Cottage.

But the spokesperson would not confirm the next tenant after reports claimed Prince Andrew is resisting a downsizing move from his Royal Lodge home to Harry and Meghan's former home.

'A year of grief, change and celebration'

The report showed £1.6m was spent on the Queen's funeral which included paying for engagements at Buckingham Palace and staff costs and travel, a palace spokesperson said.

A further £700,000 was spent by the royal household on the Platinum Jubilee.

Separate financial information relating to the Prince of Wales was also released, showing William received a private income of nearly £6m from the Duchy of Cornwall.

Sir Michael Stevens, Keeper of the Privy Purse, said the past 12 months had been "a year of grief, change and celebration, the like of which our nation has not witnessed for seven decades".

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He added: "These past 12 months have taken us from the Platinum Jubilee in the summer of last year, to the sadness of the death of Queen Elizabeth and the accession of our new sovereign in the autumn, via an incoming and outgoing state visit and many months of work in preparation for the coronation of their majesties King Charles and Queen Camilla in the spring of this year."

But Graham Smith, chief executive of Republic, which campaigns for an elected head of state, criticised the rise in royal expenditure as the country experienced a cost-of-living crisis.

He said: "Charles has suggested he's concerned about, and aware of, the cost-of-living crisis and yet he seems completely oblivious to his need to reduce costs and they continue to go up and up, whilst public services are being squeezed.

"Really they should be slashing the budget by tens of millions of pounds, not increasing it by £5m."