£1m-a-year mansion : redeveloped Lib Dem HQ rented to Middle East billionaire in record-breaking 'try before you buy' deal

The former headquarters of the Liberal Democrats has been let to an overseas billionaire family for a £1 million-a-year “try before you buy” rent after a lavish three-year renovation.

The Grade II listed Edwardian mansion, close to the Houses of Parliament, was the London base of the SDP after its formation in 1981 and the scene of some of the most momentous upheavals in recent British politics.

The Lib Dems — formed in 1988 when the SDP merged with the Liberal Party — moved out to save money in 2011.

It will be the first time that the seven bedroom house has been used as a private home and it is said that it will be the largest in Westminster.

The new tenants have agreed to pay a monthly rent of £84,000 for a year, with an option to buy for about £35 million.

It is the biggest “try before you buy” deal yet seen in London.

The arrangements are increasingly popular with foreign buyers due to the uncertainty hanging over the capital during Brexit negotiations, and the rise in the upfront costs of buying expensive homes following increases in stamp duty.

Becky Fatemi, managing director of agents Rokstone, which handled the letting, said: “This ultra-prime lettings deal shows that the world’s super-rich still want and choose to live in central London.

"Traditionally, the international super-rich would simply have purchased a property in the capital, worth anywhere between £25 million to £100 million.

“However, stamp duty, political weakness and Brexit have caused some amongst the global super-rich to delay buying homes in London. Instead, we are seeing an upturn in ‘try-before-you-buy’ mega-rental deals.

“Five years ago, there was just one of these deals, then three between 2014 and 2015, then it jumped to five in 2016 and six last year.”

The house was built in the grand Edwardian Baroque style, between 1904 and 1905, to be the headquarters of the LNER railway company.

After the renovation by developer Saigol DDC — run by former Goldman Sachs financier Faisal Saigol — the property now has five reception rooms, seven bedroom suites, eight main bathrooms with Italian “book-matched” marble and an eight-person lift.

The master bedroom suite is the size of a conventional two-bedroom flat. There is an entrance hall and grand inner hall with main staircase, a kitchen/breakfast room, study and wine room, as well as a 13-metre indoor pool, jacuzzi, gymnasium and private health spa.

The property comes with a bronze sculpture by Rodin.