VICEROYAL VILLIERS : British Occupied Ireland

Indecent exposure: Christine Keeler and Mandy Rice-Davies, surrounded by a press scrum as they leave the Old Bailey during the trial of Stephen Ward in 1963. Photograph: Evening Standard/Getty Images

Occasionally, a single passage in a book lingers long in the memory. This one will. A dominatrix who flogged men was asked why her rich clients had these tastes. "It went back to their nannies. Bus drivers and people like that who don't have nannies don't ask you to whip them," she replied.

Published to coincide with the 50th anniversary of the affair to beat all affairs, Richard Davenport-Hines's book on the scandal is a masterful depiction of everything that was wrong with the 1950s and early 1960s. Yet for all the deceit and bullying, this is a romp of a read, full of colour and verve, a mix of The Hour and Mad Men in a single volume.Thus was life in the England of the early 1960s, an era epitomised by privilege, hypocrisy and sordid glamour, by powerful men and the "good time girls" they bedded. The era bears a name: Profumo.

The reader is taken on an extraordinary tour ofpolitics and the bedroom, and the politics of the bedroom. Pretty much everyone in public life, it seemed, was having it away with someone, usually a girl (or boy) of a lower station, either preyed upon or seduced by the vague prospect of a "better" life.

Christine Keeler and Mandy Rice-Davies, the two young women at the heart of the story, were no different from others, desperate to get away from their stifling homes. "England was a country where the gravy served at main meals made everything taste alike," the author writes. It was more regimented than at any point in its history, the time of theLady Chatterley's Lover ban and backstreet abortions. "Audiences stood in respectful silence when the national anthem was played at the end of every cinema performance; pedestrians still doffed their hats… family-planning clinics did not dare to give contraceptive advice to the unmarried; every foreigner had to register with their local police station."

Keeler had lived with her mother and stepfather in a grim estate between Staines and Windsor, with no running water or electricity, and no privacy. As a teenager, she earned money babysitting, where it was normal for fathers "to kiss, fondle or rub against her". After an overture from her stepfather, she kept a knife under her pillow at night. She started working in a cabaret club in London where she met Rice-Davies. They launched themselves into society, with the "help" of a series of older men.

John Profumo, the secretary of state for war who famously had to resign after lying to Parliament about sleeping with Keeler (at the same time as Keeler was sleeping with a naval attache at the Soviet embassy), was a man of moderate intelligence. He had eased his way through Harrow and Oxford, and he knew the people he needed to know and how to climb the ladder. Married to a film star, Profumo was a breezy type who "scooted along on charm" yet was mistrusted by some because of his "Eye-tie" surname. He met Keeler at a party at the Astors' country pile, Cliveden.

The fourth and, according to the author, saddest victim-villain wasStephen Ward, an osteopath and socialite, whose sex-fuelled parties were the talk of London.Davenport-Hines vividly describes the extent to which the police, press and politicians colluded to hound Ward. It was partly an act of individual vindictiveness; it was also what was generally done to anyone who fell out with the establishment. Once Macmillan's government realised it was in trouble, everything was done to pursue Ward. One of the more bizarre charges levelled against him was the Sexual Offences Act of 1956. This included the crime of introducing any man to a woman under the age of 21 (even though the age of consent was 16) if they ended up sleeping with each other.

The levels of police corruption and press intrusion were on a different scale, a point Lord Justice Leveson might care to reflect on. "Reporters and photographers were proud of their deceptions," the author writes, "inveigling their way into houses pretending to be meter readers, equipping themselves with flowers or grapes and invading hospital rooms masquerading as relatives, waylaying children on their way from school… bribing and suborning."

The public craved to be shocked: the better the scandal, the higher the circulation. Newspapers indulged in an auction of prurience and faux indignation. "Keeler, the Shameless Slut," wrote the People. She was an "empty-headed trollop" who "smoked marijuana, loved orgies" and seldom washed. Such language about women was commonplace. The author quotes the Labour MP Richard Crossman as saying, shortly after marrying his third wife, a graduate in PPE from Oxford: "If you're going to marry, you want to marry either an alpha girl or a doormat. I married a doormat."

So sexually charged had the Brits become, the Americans were growing worried. J Edgar Hoover, director of the FBI, "became fixated on Keeler's attraction to 'coloured men' and this solidified his conviction that British sexual and security looseness was a menace to the United States".

The police were in cahoots with the worst of the hacks – just as they are now. They also did whatever it took to secure convictions. One tactic was to keep witnesses waiting for hours at the station until they were too weary to resist signing inaccurate statements. Once, Rice-Davies was arrested at the airport as she tried to leave for Spain, was taken to Holloway prison where she was "subjected to body searches, her pubic hair was shaved and she was locked in her cell for 20 hours a day". The chief inspector told her: "You don't like it in here very much, do you? So you help us and we'll help you." She told them what they wanted to hear about Ward and his parties. Ward killed himself through an overdose as his "trial" was concluding. The report by Lord Denning on the affair was a masterpiece of whitewash.

Many a book and film have been devoted to the Profumo affair. It is easy to rush to judgment. If there is a criticism to be levelled at this tale, it is the author's projection of disdain from a contemporary vantage point in which we worry incessantly about our approach to race, gender and sexuality. Public life in 1963 revolved around homophobia, with its "abasement of vulnerable individuals, prudish lynch mobs [and] the deviousness behind the self-righteous wrath of the judiciary". Fifty years on, the government is planning to recognise gay marriage. Some things do get better.

John Kampfner is author of Blair's Wars and Freedom for Sale