In the boardroom of WC Boggs and Sons, makers of fine toiletware - established 1870- Mr WC Boggs (Kenneth Williams) is testing out his latest toilet bowl for size and comfort. The guinea pig for this unusual chore is his long suffering secretary, Miss Withering (Patsy Rowlands) in the presence of the factory foreman, Sid Plummer (Sid James) and the firm's permanently employed designer, Charles Coote (Charles Hawtrey).
Meanwhile, hard at work in the packing room are Chloe Moore (Joan Sims), her crony Maud (Marianne Stone) and Bernie Hulke (Bernard Bresslaw) under the supervision of rebellious shop steward, Vic Spanner (Kenneth Cope).
But the industrious atmosphere does not last long. After a swiftly contrived dispute over tea breaks, the whole factory is on strike. This doesn't worry Lewis Boggs (Richard O'Callaghan). In fact, it is the perfect opportunity for him to date Myrtle Plummer (Jacki Piper), the foreman's attractive daughter and factory canteen girl, that afternoon - much to the annoyance of Vic, who also has his eye on her.
And so the workers all arrive unexpectedly at their respective homes for lunch. At the Plummers, Sid settles himself down for an afternoon of horses, which immediately upsets his wife Beatty (Hattie Jacques) who asks why he wastes so much time betting on them and never picking a winner. When she takes up Sid's challenge to do better, they soon notice that their budgie (who up to then has never uttered a squawk) chirps just once during Sid's reading of each list of runners from the previous day's racing - and every chirp coincides with the winner of that race. Sid has found himself a feathered gold mine, to the cost of his local bookie (Davy Kaye).
For others, the afternoon has been far from happy. After Bernie has picked up Vic on his motor bike, they are racing through town to the football match when they see Lewis picking up Myrtle in his sports car. At Vic's command to follow them , Bernie pulls away so abruptly he leaves his pall sitting in the middle of the road - minus his pants.
Vic's troubles do not stop there. He arrives home furtively, only to be greeted by the dreaded voice of his mother (Renee Houston) demanding to know what he's doing without his trousers. He looks aghast at his mother, who has emerged from here tete a tete with Charles Coote - who is lodging with them - dressed only in her underclothes, unaware that they are engaged in an innocent game of strip poker.
The afternoon has not worked out for Lewis and Myrtle either and after a series of disasters Myrtle storms out on him.
Eventually life returns to normal at the factory. Lewis has been absent for a couple of weeks, but returns with an order for 1000 bidets for a harem in the Far East. The bank manager refuses to increase the firm's overdraft to cover the initial outlay so Plummer consorts with his budgie and overcomes this problem.
But another strike is called by Vic when he discovers two of his fitters are required to do two jobs. WC Boggs is plunged into despair has he seriously faces bankruptcy.
Suddenly the workers stream back into the factory - just in time for the firm's annual outing to Brighton. And WC Boggs startles everyone by announcing he will be joining them. He even sets the toe of the trip himself, as the management and staff shed all their inhibitions in a mad scamper in and out of the hotel bar and around the pier amusement booths.
It turns out to be quite a day. Lewis, having organised a special marriage licence, chases Myrtle everywhere until they finally get married that afternoon. Knowing of Miss Withering's deep hidden passion for WC Boggs, Sid - aided by Chloe - poses as a fortune teller and puts the unsuspecting couple on the road to romance. And finally, the whole party returns home - tipsy, but totally happy.
The factory's labour problems are also about to be solved. The very next day Agatha Spanner arrives at the factory leading a regiment of women workers and wives to break the picket line organised by her son and open the factory doors. Work is resumed. WC Boggs is in business again.