A wealthy Labour Party donor has been revealed as the buyer now holding the keys to Nick Candy's £265million mansion, in Britain's most expensive house sale.

Trading firm co-founder Suneil Setiya, who also runs his own foundation to fight climate change, is the new owner of Providence House, in south-west London.

The Grade II-listed mansion, formerly the home of Britain's first prime minister Sir Robert Walpole, is located within the grounds of the Royal Hospital Chelsea and overlooks the River Thames.

Setiya made his fortune as the co-owner of Quadrature Capital, a London-based hedge fund company specialising in automated trading. 

His deal with billionaire property developer Candy, who is also treasurer of Reform UK, is thought to be the most expensive sale ever made in the UK, and possibly the world, the Financial Times reported.

Alongside his considerable wealth, Setiya is also known as a leading philanthropist.

He and business partner Greg Skinner, topped The Sunday Times' Giving List in 2025, having donated 13.8 per cent of his £980million wealth. 

The entrepreneur also donated £4million to Labour before the 2024 General Election, marking the single largest donation ever made to the party.

He is also the founder of the Quadrature Climate Foundation, which he established in 2019, to fight climate change - and has pledged £100million a year to the cause. 

The property was used to host a Reform UK fundraising bash in September 2024.

Two months earlier it was home to an event for Donald Trump's most recent election campaign that was attended by his son, Donald Trump Jr.

Candy's home was not openly marketed, but was the subject of multiple offers from interested parties, sources told Bloomberg, which first reported the sale.

The sale of the 19th century mansion, originally called Gordon House, was reportedly led by Sotheby's International Realty - and represents a whopping investment for Mr Candy.

His brother Christian bought Providence House for a reported £75million and the pair then carried out extensive renovations over four years at the Grade II listed home.

The home was made over using Nick's own in-house interior design business, Candy London, while retaining period Georgian features inside.

It boasts its own lake, an underground 60ft swimming pool and the first private Imax cinema screen in Europe. The two-acre plot also has the biggest garden in central London other than Buckingham Palace.

The reported sale price beats out the £210million paid by Chinese billionare Hui Ka Yan in 2021 for a 45-room mansion overlooking Hyde Park in London.

Mr Hui was able to exploit the weak pound post-Brexit to buy 2-8a Rutland Gate for relatively little money - all things considered - before his company, China Evergrande Group, collapsed under $300billion of debt.

The sale had been, until now, London's biggest. Last year, some 41 homes priced over £15million exchanged hands, reportedly sold off by non-doms fleeing the end of their beneficial tax status. Of those sales, three quarters were done in cash.

As well as serving as treasurer, Mr Candy is a strong supporter of Reform UK, having donated £990,000 over the course of 2025.

A well-connected businessman, he engineered a meeting between Reform UK leader Nigel Farage and Elon Musk at Donald Trump's Mar-a-Lago home in late 2024 - before Musk became a vocal critic of Mr Farage some weeks later.

Land Registry records show the house is owned by a limited liability partnership controlled by Candy and his ex-wife, the Australian singer and actress Holly Valance. The couple filed for divorce last year after 13 years.