Nat Rothschild, the financier at the centre of allegations that threaten to engulf the shadow Chancellor, George Osborne, is no stranger to laws which forbid politicians from accepting donations from abroad. Political donations from overseas are also illegal in the US, where John McCain's campaign team is under investigation for allegedly accepting a benefit in kind from two mega-rich British citizens, namely Nat Rothschild and his father, Jacob, the Fourth Baron Rothschild. In April, Mr McCain passed through London and spoke at a fund-raising dinner for expatriate Americans, where seats at the cheapest tables cost 500 a head. What caught the eye of Judicial Watch, a Washington-based foundation dedicated to combating corruption, was that the event was held by kind permission of Lord Rothschild and Hon Nathaniel Rothschild" at the family home in Spencer House, St James's, the only privately owned 17th-century palace in central London. The Rothschild family and politics have been intertwined for generations, ever since Nathan Rothschild, who founded the English branch of the family business, financed Britain's war against Napoleon two centuries ago. Serena Rothschild, Nat Rothschild's mother, was one of the largest individual donors to the Conservative Party last year. She gave 190,000. She has also helped fund Mr Osborne's office. When another member of the clan, Sir Evelyn de Rothschild, married the New York businesswoman Lynn Forester, they spent the night of their wedding dinner in the White House as guests of Bill Clinton. Lady Rothschild was a fund-raiser for the Democrats. So it is nothing new for a Rothschild to be mixing with prominent politicians.