What  does the demand soar for?
Arthur Ashton is a makeup man working for National Television (a parody of the BBC). During a visit to the local laundrette, he meets Sid Gibson a shady pedlar who is trying to flog Bonko, a brand of washing powder in the shape of a pill, but who can't afford to advertise on TV. The fairly clueless Arthur agrees to help him, and they manage to plug an advert for Bonko on National Television by interrupting the live feed. This causes quite a stir amongst the National heads, who have Arthur fired. Despite this, the advert proves extremely popular and demand for the product soars.
After repeating the stunt at Ascot Races, Sid, realising that this is potentially a huge moneymaker, does a deal with an advertising executive and, with Arthur's help, they plug cake mix at the Edinburgh Festival. After a narrow escape, Arthur wants to quit, but Sid persuades him to do one final job—interrupting a press conference between the British Prime Minister and the American President. On the way, the Post Office van they are using is hijacked by criminals. Arthur, who is in the back of the van, contacts the police to thwart the robbery, leading to the final barnyard showdown. In the end, Arthur, now a hero and celebrity, gets his own TV show, brokered by Sid, of course.
Bonko