The Prime Minister and Chancellor are preparing a puritanical budget taxing amusements such as bingo, gambling and night-clubs out of existence. On the afternoon before its presentation, however, each in turn appears to be the father of the pretty Shirley, the result of a post-party conference night many years ago. In an even less expected family bombshell, it transpires that the Prime Minister's deferential Parliamentary Private Secretary, Campbell, is, in fact, his son ...