Set in 1944, in the fictional seaside town of Walmington-on-Sea, the film stars Toby Jones as Captain Mainwaring, the leader of an elderly platoon of the Home Guard that comprises Oxford-educated Sergeant Wilson (Bill Nighy), doddery Private Godfrey (Michael Gambon), excitable Lance Corporal Jones (Tom Courtenay), cantankerous Scot Private Frazer (Bill Paterson), dim-witted Private Pike (The Inbetweeners‘ Blake Harrison) and spivvy Private Walker (Daniel Mayes). Charged with defending the coastline should the Nazis invade, Mainwaring and his troop are warned to be on the lookout for a German spy, but their attentions are distracted by the arrival of glamorous journalist Rose Winters (Catherine Zeta-Jones) who’s come to write a piece on the Home Guard. However, the star of the show is undoubtedly Toby Jones, who proves himself adept at both physical comedy (bumping into things without his glasses on; trying to answer a phone while his arms are strapped to a plank of wood) and verbal dexterity, delivering a series of delightful line readings, accompanied by an impressive range of guttural spluttering sounds. Indeed, the only duff note in the casting is Zeta-Jones, whose character is disappointingly one-note, despite a promising early reveal in regards to the plot. The film also gains points for subtly evening up the gender balance. Having made the decision to give Mrs Mainwaring (always offscreen in the TV show) a physical presence in the form of Felicity Montagu, the film expands that idea to include a whole Ladies Auxiliary movement (including Sarah Lancashire, Alison Steadman, Annette Crosbie and Julia Foster), who are inevitably dismissed by the men (Mainwaring even does an eye-roll at one point), but of course end up proving a thousand times more useful, whether engaging in Miss Marple-style detection (Crosbie and Foster, very amusing) or weapons proficiency. Plot-wise, the film meanders considerably in the middle section, more or less as you’d expect from a sitcom plot dragged out to feature length. However, Parker does manage to pull off a surprisingly decent climax with what passes for an action sequence, given its mostly geriatric cast. The main question with the film is exactly who it’s aimed at – ‘Who do you think you are kidding, Mr Parker?’, if you will – as the majority of younger cinema-going audiences will have little to no familiarity with the show outside of the BBC’s current reruns. Still, perhaps the filmmakers are banking on a contingent of die-hard fans of the show parting with their grey pounds – either way, they will take comfort from the fact that the aforementioned BBC repeats routinely draw in around 3 million viewers. Ultimately, it’s a pleasure to watch this group of actors bouncing off each other and it’s fair to say that fans of the show won’t be too disappointed, even if the film’s never quite as funny as it could have been. Despite its thinly-stretched plot and lack of big laughs, it’s never less than watchable and retains an amiable gentleness that leaves you feeling surprisingly warm towards it. Dad’s Army is in UK cinemas from Friday. Follow our Twitter feed for faster news and bad jokes right here. And be our Facebook chum here.