For more than a decade, Anthony Bamford and his family have commanded power and influence as some of the UK’s most politically active, Brexit-backing billionaires. His prominence increased during Boris Johnson’s premiership: he footed the bill for the then prime minister’s wedding party. It was his lawn, at his Cotswolds country estate, that played host to the marquee, hay bales and a South African-inspired barbecue when Chequers – the country residence of British leaders – was rendered unavailable to the couple after Johnson’s political downfall. The Bamford dynasty is not just a donor but a “super-donor”, according to a study of donor clout in elections by the University of Warwick. Lord Bamford’s super-donor status may make the Guardian’s report that his tax affairs are subject to investigation uncomfortable reading for the Tory party. From his Daylesford country seat in the Cotswolds, and his London townhouse near Harrods in Knightsbridge, Bamford has entertained prime ministers, brokered global business deals and helped determine the course of British politics for the past 13 years of Tory rule. At 77, he still runs the multibillion-pound JCB empire he took over from his father, Joseph Cyril Bamford, in the 1970s. The manufacturing business, founded in 1945, has grown into an internationally recognised brand where the three initials immediately spark the mental image of a yellow digger. Its commercial links from Staffordshire to India and beyond have been a matter of close scrutiny, with questions raised over sales of JCB diggers in sanctions-hit Russia by a third-party distributor. JCB says it voluntarily ceased supplying equipment to Russia soon after the invasion of Ukraine. Politics is very much a family affair for the Bamfords. Lord Bamford has made donations in his name via companies he controls alongside his brother Mark, but it has often been Mark who has personally signed off on million-pound cheques, according to data gathered by the Electoral Commission. Lord Bamford’s son Jo has made donations in his own right, supporting the former chancellor and Conservative party chair Nadhim Zahawi’s office in Stratford-upon-Avon. Lord Bamford is a director of the Centre for Policy Studies, Margaret Thatcher’s favourite thinktank, known for its libertarian, low tax, pro-business, small state philosophy. From weddings to luxury hampers, Lord Bamford and his wife, Carole, are particularly close to the Johnsons. They gave the couple use of a cottage on their estate and their personal townhouse – at what the MPs’ register of interests suggested were non-commercial terms – allowing the Johnsons to sell a south London property more efficiently. They consider Boris and Carrie to be “like family”, according to insiders, and “nothing is too much” for the former PM. The Johnsons’ new large country home is just over an hour’s drive from Bamford’s Daylesford estate. It was another former prime minister, David Cameron – who also lives near Bamford’s country estate – who steered his course towards a peerage in 2013. It was a bumpy road to get there: Bamford had a flag raised about his tax affairs that led him to withdraw from the appointments process in 2011, something he addressed publicly with an interview in the Evening Standard, saying accusations of irregularities in his tax affairs were “utterly untrue”. Other Conservative prime ministers have found that falling out of favour with Bamford contributed to their downfall. “Losing the money,” as it is sometimes described by those who have to chair political parties, can sound the death knell for a prime minister on the edge of an ousting. Theresa May’s beleaguered No 10 certainly viewed the loss of Bamford’s favour as a nail in the coffin, according to one former insider. May’s coffers were boosted by the Bamfords for her election in 2017, only for the JCB boss to play host to her key rival Johnson in 2019. The peer, a strong supporter of Brexit, disagreed with her pursuit of a deeper trade deal with the EU rather than trading on WTO rules (the hardest possible outcome), something Bamford said was a route “worth taking”. By January 2019, Bamford was hosting what many political observers regarded as the soft launch for Johnson’s successful leadership campaign. Once Johnson quit No 10, Bamford lent his backing to Liz Truss’s bid for power, favouring the candidate whom many in the party had regarded as the least aggressive towards Johnson when he came under pressure over Partygate and the Chris Pincher affair. Bamford’s criticisms have also triggered moments of discomfort for the latest Downing Street incumbent, Rishi Sunak. The prime minister’s position on electric vehicles and promotion of battery technology over hydrogen vehicles (which the Bamford family are developing) was “shortsighted”, Bamford said in a press release in April this year. He publicly lashed out about the “mammoth” tax levels in the UK, telling the Sunday Times in July: “Isn’t the country in a mess now?” But Britain’s messiness or otherwise has not deterred Lord and Lady Bamford from building up a mini lifestyle empire in the Cotswolds, built around the Daylesford organics and wellness brand. Locals say it is steadily encroaching into the villages of Oddington and Kingham – both close to the Daylesford farm shop and its restaurant – in order to expand offerings of guesthouses and activities for paying guests at the estate. Bamford also owns a collection of luxury sports cars, including a rare Ferrari GTO. Whether a tax investigation will affect the level of influence Bamford and his family have held for decades is unclear. But it will certainly raise questions about the business titan’s next moves.