Sir William Mainwaring-Brown, a British Government Minister, puts forward a bill to battle filth (permissive behaviour) in the UK. However, that doesn't stop him having an affair with both Miss Parkyn (his secretary) and Wendy (the wife of a high-up reporter).
Opponents to the bill - mainly some hippies, led by Johnny - kidnap the Minister's best friend and co-sponsor of the bill, Barry Ovis, just as he is on the way to the church to marry his fiancee, Jean.
Later and following a tip off by Johnny, the police raid the hippies' flat. The intention is to discredit Barry Ovis by making it appear that he was involved in an orgy and therefore, remove any credibility that the Law and Order Bill might have had. Thankfully (for Barry), he escapes before the police discover him and dashes back to Sir William's flat followed by Edith, one of the hippies.
Meanwhile, the Minister is also trying to use the flat to carry on his affairs with both Wendy and Miss Parkyn. The Minister, Barry and Jean try to keep the truth from Inspector Ruff, Wilfred Potts (an ancient MP, who is staying temporarily in the adjoining flat) and Birdie (the Minister's wife). Not only that, but they have to try to deal with the hippies who do their utmost to discredit Mainwaring-Brown and Ovis. Naturally this causes no end of trouble.