The plan: to transport 10,000 salmon from the UK to the less conducive environs of the Middle East, where a fishing-obsessed sheikh wants to cast his rod.

Such a preposterous premise is fair enough, if you can pull it off. By all accounts, Paul Torday's satirical novel Salmon Fishing In The Yemen does. This film does not.

It's an odd watch. Its antiquated nature has a certain charm, for a bit, until reality catches up with it and our patience wears thin. I'd love to recommend it for a typically self-effacing and amusing performance by Ewan McGregor, another captivating one by Emily Blunt and an atypically comic turn by Kristin Scott Thomas. But ultimately the salmon are not the only ones swimming against the current.

McGregor plays Fred Jones, a fisheries expert for the government who is seconded, much against his will, to advise the Yemeni sheikh (Amr Waked) on his dream of introducing salmon to his country. For the sheikh, not as dumb as he might seem, the fish are merely the icing on the cake of his real agenda to bring water into Yemen's arid hinterlands; for British spin doctor Patricia Maxwell (Scott Thomas) it's a positive news story, a symbol of Anglo-Arab relations. But Jones sees only hubris and folly.

The set-up is quite enjoyable – in a sort of TV sitcom way – as the staid and pompous Fred spars with the sheikh's beautiful and bright English representative, Harriet Chetwode- Talbot (Emily Blunt). Since he is unhappily married and her soldier boyfriend disappears in Afghanistan, the jolly antagonism will inevitably lead to love and the stars' rapport believably conveys the burgeoning affection.

Scott Thomas's bullish spin-doctoring is also very enjoyable in the early stages. The mistake of the film is not to stick to the political satire inherent in her character, instead opting for syrupy romance and unlikely melodrama. As the plot becomes more serious, with the sheikh's British-hating enemies seeking to assassinate him, so, conversely, the approach seems ever more trite.

I'm not entirely sure why authors let Lasse Hallström anywhere near their work. The Swedish director has a habit of maximising the feelgood aspects of his material, whatever its underlying edge, to such a degree that we come to entirely resent it. Since his first (and best) films, My Life As A Dog and What's Eating Gilbert Grape?, his style has become increasingly pedestrian. The only thing that would stop you being appalled by the end of this film is the fact that you may well be asleep.

Scottish director Kevin Macdonald made his name with two films that helped to rewrite the book on documentary form: One Day In September and Touching The Void were original, dynamic, exciting pieces of work. Ironically, given the colourful and tumultuous reality of Bob Marley's life, Marley is altogether more conventional, and a lesser film for it.

At two-and-a-half hours, this is a thorough trawl through the reggae superstar's life and times, from his poor upbringing in Jamaica, the formation and success of the Wailers, the embroilment in Jamaican politics which led to an attempt on his life, and his eventual tragically early death from cancer. Although the archive material is fascinating and the range of interviewees impressive, the sheer weight of it feels laboured and slightly hagiographic, as though absolutely everyone had to have their say.