Unlike Dixon of Dock Green, it did not begin with a reassuring uniformed salute. Instead, The Sweeney exploded on to TV screens in 1975 with threats, intimidation and violence. Grainy, adult and ultra-realistic, never before had a British police drama portrayed crime fighting on London's streets quite so authentically. Cops were as hard, ruthless and darkly glamorous as the villains they nicked, and liked smoking, drinking and bedding women - on and off duty. Then there were the thrilling car chases around grubby streets and derelict docks, where police in souped-up Ford Granadas hurtled after armed robbers in old Jags, and the punch-ups which saw cops and villains battering each other senseless against brick walls and chain-link fences.Focusing on the exploits of the Flying Squad, the Metropolitan Police's elite CID unit, the series made overnight stars of John Thaw and Dennis Waterman - playing bantering detectives Jack Regan and George Carter - and featured an array of guest stars, from John Hurt, George Cole and Diana Dors to Patrick Mower, Lynda Bellingham and Morecambe & Wise. Shot entirely on location on 16mm film, the show pioneered a new way of making quality TV drama in the UK that soon became the norm. Thirty years after it ended, when Gene Hunt swaggered on to our screens in Life on Mars to give a masterclass in old-school policing at the end of a fist, Britain was still paying homage to The Sweeney, and it was regularly being repeated on cable TV channels.

Now, in Shut It!, Pat Gilbert investigates the culture of law and order in the '70s that inspired and shaped the series, and talks to actors, writers, directors, producers, crew and real-life Flying Squad officers about their experiences working on the show. Here, then, are the behind-the-scenes bust-ups, on-set brawls, mythical drinking sessions and intriguing backroom secrets - the story of how Britain's greatest ever cop show was made.So, get your trousers on, you're nicked.