THE royal household now costs the taxpayer more than £500 million a year in a “scandalous abuse of public money”, according to a new report.

Anti-monarchy organisation Republic has compiled a 27-page report entitled The Half a Billion Pound Royals laying out how much the public are forking out to support the lavish lifestyles of King Charles and his family.

The estimated price tag of £510m includes hundreds of millions of pounds not accounted for by the Sovereign Grant – a payment that is made annually to the monarch to help fund their official duties.

Elsewhere, the campaign organisation is calling for Charles to have a salary pegged to that of the Prime Minister, for an end all royal exemptions from the Freedom of Information Act, and an “honest and public” inquiry into royal finances and spending.

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Republic has said the bill for the royals includes lost income from the Duchies of Lancaster and Cornwall, as well as an estimated £150m security bill, costs to struggling local councils and lost revenue from state buildings used exclusively by the royals.

Republic CEO Graham Smith said: “The half a billion pound cost of the royals represents a scandalous abuse of public money.

“If Rachel Reeves thinks tough decisions are needed in these difficult times, she needs to start with the royals.

Prince William and his father earn vast amounts from the Duchies of Cornwall and LancasterPrince William and his father earn vast amounts from the Duchies of Cornwall and Lancaster (Image: Russell Cheyne/PA Wire)

“We're being told the budget will be painful. Well if that's true, the cuts must start at the top.

“The Sovereign Grant is spiralling out of control, set to rise by another £45m a year. Yet the true cost of the monarchy is well over half a billion pounds, and most of that is because the royals spend hundreds of millions a year on their own private lives.

“Republic is demanding the royal budget be slashed to below £10m, that only Charles receive any public funding, that he is given a salary pegged to that of the prime minister and that MPs hold a inquiry into this appalling waste of money."

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It was confirmed in July that soaring profits from the Crown Estate to £1.1 billion mean the taxpayer-funded Sovereign Grant will increase from £86.3m in 2024/2025 to £132m in 2025/2026.

Tristan Gray, treasurer for Scottish anti-monarchy group Our Republic, said: "As the Government in Westminster argues for the necessity of a harsh budget to come, it seems no such requirements are being asked of the billionaire family that rules over our laws and land.

"If the Monarchy truly are to be considered figureheads, examples to the country as a whole, and selfless servants of it - maybe they should be the ones who are asked first to cut back on their hundreds of millions in expenses ahead of our public services."

Republic says the new report provides “irrefutable evidence” that the two Duchies are state property and not private estates, yet they provide King Charles and Prince William personal incomes in excess of £23m a year each.

For centuries a debate has raged over who really owns the duchies, and who is entitled to their profits: the royals or the people.

Smith went on: “This new report shows unequivocal proof that the Duchies are state property, not private estates. That means we effectively pay William a personal income of £23m a year.

"The royals are dishonest in claiming otherwise. The Duchies have been Crown property for hundreds of years, the parliamentary and historic record makes it clear they are not private estates."

Campaigners hope the report will fuel a debate about abolishing the monarchy “in favour of a democratic and accountable alternative”.