Sleep with the fishes: "Salmon Fishing in the Yemen"

The conceit sustaining Salmon Fishing in the Yemen is right there in the ungainly title: nobody goes to the desert to catch fish. (Boom boom.) Everything else is offered as compensation. Emily Blunt plays Harriet Chetwode-Talbot ("call me Harriet"), posh totty attempting to fund a deal involving a fish-mad Yemeni sheikh. Ewan McGregor is the buttoned-down fish expert (wardrobe: V-neck pullovers by day, PJs by night) Harriet calls in to oversee the details. Naturally, this being a modern romcom, the pair are roomed in adjacent suites for the duration, and naturally, both have existing partners, which prove useful when it comes to padding out Act Three: he a wife who appears more like a live-in assistant, with whom he enjoys very functional, PJs-on missionary sex, she - in a nod to real-world seriousness - a hunky soldier boy handily called away to Afghanistan just as the project is getting going.

Whatever creative thought was expended once the deals were signed to film Paul Torday's bestselling novel has gone on figuring out how to liven up what must, even on the page, have seemed a perilously dull milieu for an affecting romance to spring from, all meetings with engineers and international development ministers. Lasse Hallström (for it is he) plumps for split-screens, on-screen emailing and instant messaging (always a lameness klaxon), and sending on Kristin Scott Thomas to pep things up, albeit in the ludicrous, cartoonish role of a 12A-rated Malcolm Tucker, who uses the term "effing" rather than its real-world equivalent.

If I appear unduly unfussed by the result, that's because Salmon Fishing proceeds in a register to which I've grown all but deaf: that of the romantic trifle that takes place within romcom world rather than reality, with characters who are obvious composites of other romcom characters, rather than individuals with feelings at stake. This one takes place in a romcom Yemen, which is a novelty, but the problem remains. McGregor and Blunt are appealing presences, but they're limited by having to bring colour and shading to cut-and-paste characterisation: the very literary archetypes of "the lonely specialist" and "the heartbroken soldier's girl", respectively.

While the film stays within its middlebrow wheelyard, it is at least unobjectionable: something you could happily doze off to on a Sunday afternoon, confident you wouldn't miss anything unexpected or challenging, a phoney with a couple of half-decent, well-played scenes to distract you from its phoniness. It's when it tries to make contact with the real world again that Salmon Fishing gets into trouble, for this is - after all - a film dealing in some sense with the Middle East, even if it is a romcom Middle East. (You dread to think what may be round the corner if this does any business: Jennifer Aniston and Josh Duhamel in a romcom set on the West Bank, provisionally entitled What's Your Occupation?) Hallström is too blithe a director to do political intrigue, which makes very flimsy the pivotal scenes in which McGregor thwarts an assassination attempt by casting off, and men wearing headscarves and paramedics carrying bodies on stretchers start running around; by then, however, the gears of the plot have begun grinding away to contrive the happy ending, sealed with a leaping CG salmon. It'll play well to an older crowd, which - in the absence of more viable alternatives - has become the movies' favourite euphemism for "it ain't much cop, but it fills a gap in the market".

Salmon Fishing in the Yemen opens in cinemas nationwide today.