A pair of billionaire brothers want to transform this dilapidated property into the UK’s most expensive home worth more than £200 million.
Property tycoons David and Simon Reuben bought Cambridge House on Piccadilly last year.
They have now submitted plans to Westminster Council to turn the run-down building into one of the world’s most impressive private homes.
The Grade I listed building, overlooking Green Park, was designed by Matthew Brettingham for Charles Wyndham, 2nd Earl of Egremont in the 1750s.
It later became the private home of 19th century Prime Minister Lord Palmerston before The Naval and Military Club turned into one of the city’s most exclusive members clubs.
But it has fallen into a state of disrepair following years of neglect with the Reuben brothers instructing Paul Davis and Partners to restore the property to its former glory.
However, because of its Grade I listing the team will have strict planning regulations to abide by and will have extensive dealings with Westminster Council and English Heritage.
They plan to turn the 50,000 sq/ft building into a 48-room residence with underground swimming pool, gym and 35,000-bottle wine cellar.
It has been estimated by estate agents that the property, which is located in the heart of the capital, would be marketed for around £214 million when completed.
The most expensive house ever sold in the UK is Park Place near Henley-on-Thames in Oxfordshire which was sold to Russian billionaire Andrey Borodin last year for £140 million.
Motcomb Estates, acting as advisors to the Reubens, have submitted applications for planning, listed building and conservation area consent to “bring the Grade I ‘In and Out Club’ and the neighbouring buildings on Piccadilly back into use, after over a decade of neglect”.
In a statement, the company added it wanted to refurbish the buildings and “restore them to their former glory as grand residential properties”.
Trevor Abrahmsohn, who runs Glentree Estates selling properties on this scale, described the home as a “great opportunity” for a wealthy foreigner to buy a piece of English heritage.
But the estate agent added it is unlikely anyone will know when the completed home changes hands.
He said: “It would make a wonderful home and be one of the largest private residences in the UK.
“No one has got much more than £120 million for a home in London but that is not to say it wouldn’t happen.
“This is a unique property and a great opportunity for a very wealthy person who wants a landmark home in London.
“For them, it is about buying a piece of English heritage but you won’t know when it is has been sold.
“Properties like this will be sold through the grey market – when no information is made public.”
The Reuben brothers, who started out importing carpets and buying real estate, moved to the UK as teenagers after growing up in Bombay.
They are ranked as the eighth richest people in Britain according to The Sunday Times with a fortune estimated at £7 billion.