'You're a pretty girl' - Cameron's unPc uncle talks about his book

I feel like Dominique Strauss-Kahn," says Sir William Dugdale as he poses for his photograph in his bedroom at the Ritz Hotel. His eyes settle on the print on the wall, Velázquez's nude Rokeby Venus, lying on a divan gazing at herself in the mirror.

"Rather nice," he says. "Well-upholstered back end." This is David Cameron's uncle by marriage. At 89, his admiration for women is undiminished. His wife, Cylla Mount, the sister of David Cameron's mother Mary, perches politely on the end of the bed.

He has always flown the flag as the adventurer of the family. His autobiography Settling the Bill, which has just been privately published, lays bare his antics with Oxford's Bullingdon Club, his success with Italian women during the war, his love of horses, fast cars and aeroplanes, his time as chairman of Aston Villa football club and the Severn Trent water company and his service as a leading Tory on Warwickshire County Council. Tonight he is throwing a party at a gallery in Dover Street to mark the publication. The Camerons are invited but have yet to confirm.

The future Prime Minister was closest to his raffish uncle Bill in the Seventies, when he would stay at Blythe Hall, the Dugdales' Warwickshire home. Sir William had married Cameron's aunt Cylla in 1967 after the death of his first wife, Belinda. "The Camerons' two boys and girls came up. The boys liked shooting and football, which I could provide. David and [his brother] Alexander were both very keen to go to the football." Bill is chuffed that it stuck with him. "I was pleased when he said he was still an Aston Villa fan."

While he may still support Aston Villa, Cameron prefers not to reflect on his days at Oxford University's notorious Bullingdon Club, which he regards with "deep embarrassment". Uncle Bill, also Eton and Oxford educated, is from an earlier, prouder, generation. "When I was a boy, my one ambition was to get a white tie and tails and to go out and cut a bit of a dash," he says, laughing. While at Oxford in 1940, he was called up by the head of the Bullingdon to throw soot and water over a demonstration led by Tony Crosland and Roy Jenkins, both later big beasts of the Labour Party, in favour of Russia's invasion of Finland. Dugdale was arrested by a soot-covered policeman.

It was the beginning of a life of privilege and high jinks but also of service and civic duty - the big society with a hearty smile. Sir William left Oxford early to join the Guards serving in North Africa, Italy and Germany, where his heroics earned him the Military Cross. "When the Germans appeared, one defended oneself and eventually a gong appeared," he says casually. He also keenly remembers the beautiful Italian women he flirted with.

He went on to marry Belinda and they had four children but she died in 1960 from complications from an ovarian cyst. Six weeks later Dugdale was at a petrol station in London on a Friday night, en route to Blythe, when a young woman asked him for a lift home, then invited him in. He stayed for two nights and returned home to a raised eyebrow from the Nanny who had been looking after his motherless children. Surprisingly honest, he called it his "catharsis".

He went on to marry Cylla, and have two more children. The Severn Trent water board followed, along with fast cars - a Jensen and a Mercedes - and learning to fly. He was Aston Villa club chairman from 1975-1982.

There is something of Cameron's up-for-anything self-confidence in Dugdale - perhaps what our PM might have been like if he had been born a generation or two earlier. They are not close now but still see each other on family occasions. "I went to have lunch with him the other day. He's just as nice as ever. I sat next to his wife, who was charming."

Unlike his nephew, Dugdale is untouched by political correctness. At one point in our conversation he leans towards me and says, "You're a pretty girl, it's not hard for you to attract attention. Some girls look like the back ends of buses." His wife, still perched on the bed, smiles tolerantly.