Richard Smith is probably best known for flying David Cameron to his home in Shobdon, Herefordshire in 2007 – shortly after the then leader of the Opposition proposed taxes on unnecessary flights.
But the Midlands businessman also plays a low-profile but prominent role at the centre of right-wing politics.
Other permanent residents of 55 Tufton Street include UK2020, the think-tank chaired by the climate sceptic former Environment Secretary Owen Paterson.
Another resident is Civitas, the think-tank which, along with the Institute of Economic Affairs situated just around the corner at 2 Lord North Street, has been used to bolster the case for Brexit by Vote Leave.
The group is led by the Tory MP Bill Cash, who has previously served as a vice-president of Eurosceptic campaign group Conservatives for Britain.
• Civitas This think tank describes itself as ‘classical liberal’ and non-partisan.
HR Smith is a group of companies working in advanced aerospace technologies.
Mr Smith owns No 55 Tufton Street through one of his companies which bought the property on 31 December 2009 for £4.25m.
Tucked away on the side streets of Westminster, 55 Tufton Street looks like just another town house.
But this low-profile four-storey block, a stone’s throw from Parliament, is home to no fewer than eight right-of-centre organisations dedicated to pulling Britain out of Europe and undermining the battle to curb global warming.
This puts the foundation in the same building as the Tax Payers’ Alliance, the bullishly effective low-tax pressure group whose founder Matthew Elliott is now masterminding the Brexit campaign Vote Leave – which has just appointed Lord Lawson as chairman.
Vote Leave, which also involves climate-sceptic politicians such as Graham Stringer, Douglas Carswell and Dan Hannan, was originally registered at 55 Tufton Street but recently moved to a bigger office nearby.