WIth space for flunkeys and finery, this is the plan for a huge new ‘iceberg’ basement to make room at Kensington Palace.

As revealed by Sebastian Shakespeare in Saturday’s Daily Mail, the proposed enormous two-storey underground extension would be dug next to the 18th century Orangery to ‘free up the palace suites for the Royal Family’.

The local council, Kensington and Chelsea, has restricted residential two-storey basements because of the disruption they create but officials will probably ‘make an exception’ for the royal development, documents show.

Above shows a plan of how Historic Royal Palaces plan to use their underground extension, which would be dug next to the 18th century Orangery

A planning application to extend the basement was put in to Kensington and Chelsea council by Historic Royal Palaces

More than £4.5million of taxpayers’ money has already been spent on William and Kate’s Apartment 1a at Kensington Palace, which has 22 rooms and two kitchens

The 165ft-long mega-basement will make room at the palace, where the Duke and Duchess of Cambridge are due to move full-time with their children this autumn after William ends his two-year pilot’s job with East Anglian Air Ambulance and takes on full-time royal duties.

The grade I-listed Orangery – described in the plans as an ‘elaborate greenhouse in the style of an elegant palace’ – was built in 1704 on the orders of Queen Anne who wanted to protect her citrus trees in winter. It is currently used as a restaurant for visitors to the palace grounds.

The extension at the back of the historic building would provide more than 1,500 sq m of extra space over three floors. Two would be below ground with the one above built in buff brick with red brick detailing.

Some of the 100 staff working at the palace could move out of their offices and into the extension, which will also house a ceremonial dress collection.

The top basement floor will be home to staff offices, with light wells providing ‘light and air’.

The planning application says: ‘The addition of a basement storey is required to allow for the accommodation of administration which must necessarily be moved out of rooms leased from the Royal Household in Kensington Palace.’

The application has been put forward by Historic Royal Palaces, the charity which looks after the state apartments at the palace.

The 165ft-long mega-basement will make room at the palace, where the Duke and Duchess of Cambridge are due to move full-time with their children this autumn

Princess Eugenie (left) is moving to a cottage in the palace grounds later this year with her boyfriend Jack Brooksbank, while Meghan Markle (right) is said to have visited boyfriend Prince Harry in his residence, Nottingham Cottage

A council decision on the proposal is expected by the end of next month.

More than £4.5million of taxpayers’ money has already been spent on William and Kate’s Apartment 1a, which has 22 rooms and two kitchens.

Prince Harry lives in nearby Nottingham Cottage where he has been visited by girlfriend Meghan Markle.

Princess Eugenie and boyfriend Jack Brooksbank are moving to a cottage in the palace grounds later this year.

Kensington and Chelsea began restricting iceberg basements at residential homes – and banned them at listed properties – after huge outcry about the disruption the projects generate.

However, it still gave planning permission for 362 basement extensions of more than one storey in 2015/2016 alone.

The underground extensions have been popular with the rich and famous who want to expand their homes to accommodate gyms, indoor pools and cinemas.

But last year ministers were urged to put tougher restrictions on such developments.

Queen guitarist Brian May is among those to have protested over such developments, which he says have turned his West London neighbourhood into a ‘hellhole’.