The 22nd Carry On film was the last to feature any notable fantasy element. It was also a rare misfire for the usual team of producer Peter Rogers, director Gerald Thomas and writer Talbot Rothwell, the first box office flop in the series’ history. This failure has largely been attributed to the film’s theme – this time, the satire was turned on the British trade unions whose 70s power is still reviled in some quarters even now. Given that the series’ core audience was staunchly working class, it was a less than clever move, presenting the people charged with protecting the workers from management as pedantic idiots and the film seems to have rubbed people up the wrong way.

Having been accused of indulging in toilet humour for many years, the Carry Ons playfully, self-deprecatingly went along with it, setting the film in the premises of W.C. Boggs & Son (the grounds of whose factory is “played” by the wood storage area at Pinewood Studios), manufacturers of quality toilets. Owner W.C. Boggs (Kenneth Williams) is reluctant to move into the manufacture of bidets designed by Charles Coote (Charles Hawtrey), union representative Vic Spanner (Kenneth Cope) and his dopey sidekick Bernie Hulke (Bernard Bresslaw) are constantly calling the reluctant workers out on strike at the slightest whim (usually so that they can go to local football matches) with a cry of “everybody out!” on loan from Miriam Karlin in the small screen sitcom The Rag Trade (1961-1963), and there’s a Romeo and Juliet-like romance brewing between boss’ son Lewis (Richard O’Callaghan) and canteen worker Myrtle (Jacki Piper), daughter of foreman Sid Plummer (Sid James). Sid gets some luck when Joey, the budgerigar owned by his wife Beattie (Hattie Jacques) starts correctly predicting the racing results but has less luck with co-worker Chloe Moore (Joan Sims) who lives next door with travelling salesman husband Fred (Bill Maynard). It all culminates in a riotous works outing to Brighton, birthplace of the saucy postcards that were the ancestors and chief influence on the series.

There are some genuinely good moments here – Patsy Rowlands is on fine form as Bogg’s lovelorn secretary, Renée Houston is marvellous as Vic’s formidable mother, eventually putting him over knee and giving him a long-overdue spanking, there’s a visit to a restaurant/bar named The Whippit Inn and a trip to the cinema to watch fictional banned-by-the-BBFC sex education film The Sweet Glory of Love. And the performances by the regulars are spot on, James in particularly reigning in his usual lecherous characteristics and playing Plummer something more akin to his Sid Abbott from television’s Bless This House (1971-1976) and the effect is to make his character more likable than usual. Even his lusting after Chloe eventually goes nowhere, a rare failure for the various Carry On Sids. Elsewhere, Hawtrey, Sims and Williams are bags of fun but they’re really just playing characters that we’ve seen many times by now.

But it’s not hard to understand why the film didn’t click with its target audience. Announced as Carry on Comrade, the script feels like it’s lashing out at unions, tarring all union members with the same unpleasant brush and those working class viewers who had stuck wit the series during its glory years in the 1960s must have felt as if the film was taking a swipe at them. at the end, the union even capitulates and gives in to the managers which would have gone down like the proverbial lead balloon. Such was the scale of the film’s failure at the box office, in fact, that the film’s not exactly extravagant budget wouldn’t be recouped until 1976.

The budgie is a fun wrinkle, its unswerving accuracy in predicting the winners changing Sid’s fortunes. Unfortunately, it’s rather forgotten as the film goes along – if it really was that good, who on earth would Sid ever go back to work and be the middle man between the old-fashioned and pompous Boggs and the irritating Vic? Why would he not just live off the earnings from his gambling? It seems like a gag that Rothwell cooked up and then forgot about as the script goes off on a different tangent. One noticeable aspect of the script that does work is that Rothwell allowed himself a few more downbeat moments. The unrequited lust between Sid and Chloe is unusually sensitively handled and shot through with a dash of melancholy, an unusual element to find in a Carry On film.

Carry on at Your Convenience is an unusual one then, and time has been kind to it – the gratuitous union bashing now just looks ludicrous and so over-the-top as to be hard to take at all seriously and the toning down of the lecherous Sid character (the character would be similarly subdued in Carry on Matron (1972) though he’d be back to his old ways in Carry on Abroad (1972)) helps. It’s a more spirited film that Carry on Up the Jungle (1970), but the writing was definitely on the (toilet) wall and the series would become far more hit and miss from this point on, hitting the buffers with the terrible Carry on Emmannuelle (1978) before the hideous, best-not-talked-about attempt at a revival in Carry on Columbus (1992).