The Grade II listed site, which is within walking distance of Downing Street, has housed the offices of politicians including Sir Winston Churchill, David Lloyd George and Herbert Asquith over the last 100 years.
It was sold by the Ministry of Defence to a consortium led by India’s Hinduja Group in 2014, which plans to create one of London’s ‘finest luxury destinations’.
Raffles, whose Singapore hotel houses the Michelin-starred Shinji restaurant – which was ranked 21st in Asia’s 50 Best Restaurants last year - is to take on management of the site.
Planning permission has been granted for a multi-use development including restaurants, 125 hotel rooms, and 88 private homes.
“Raffles brings a unique understanding of British heritage and tradition that will help revive this great British landmark,” said Hinduja Group’s co-chairman Gopichand P. Hinduja.
The development is expected to be completed in 2020.