Britain's Queen Elizabeth is set for a £2.8m pay rise next year.

Queen Elizabeth

Queen Elizabeth

The 90-year-old monarch is in line to receive £45.6m in 2017/2018, a 6.5 per cent increase on this year's £42.8m from taxpayers, after her Crown Estate's value rose 9.7 per cent to £12 billion.

The sovereign grant - the taxpayers' annual contribution- is calculated at 15 per cent of the Crown Estate surplus. It is reviewed every five years and can only be changed by the Prime Minister, the chancellor and the Queen's keeper of the Privy Purse.

Sir Alan Reid, Keeper of the Privy Purse, said that, excluding security, the cost of the Queen's official duties and property maintenance last year, came to £62 per person.

However, he explained: "Despite increased investment the condition of the estate is deteriorating at a faster rate than we have been able to respond."

Meanwhile, the Queen is renting out two apartments at St James's Palace.

Apartment 29a, a four-bedroom maisonette, has been let on a three-year lease, and it is thought the tenant is paying £20,000 a month.

It was renovated with £500,000 of public money and boasts new bathrooms, kitchens and carpets.

A senior royal aide said the palace would get a "very quick payback on that investment".

Apartment 29b - whose neighbours are Princesses Beatrice and Eugenie - is thought to be even more luxurious with the occupant paying £250,000 a year.

The lets helped the queen net £2.9million in property rental income.