Based on an Arthurian legend, 'Tristan & Isolde' is a story of forbidden passion (memories of 'Romeo + Juliet'), set against a backdrop of political upheaval (like 'Braveheart') and featuring a tragic love triangle (remember 'King Arthur'?). Take those three films, throw in the king of MOR sword-swinging and crossbow filmmaking, Kevin Reynolds ('The Count of Monte Cristo', 'Robin Hood: Prince of Thieves'), and you've got the sentimental medieval romance that is 'Tristan & Isolde'.

Reynolds, together with scriptwriter Dean Georgaris, portrays England during the Dark Ages as an unstable land where rival tribes are constantly at each other's throats after the ending of the Roman Empire. An Irish king, Donnchadh (O'Hara), spends his time actively encouraging the instability in order to maintain - and this is undoubtedly a new twist - Ireland's rule over England. Tristan (a petulant performance from Franco), who grew up with a hatred of the Irish after they killed his family, was brought up by father figure Lord Marke (Sewell). Across the Irish Sea, Donnchadh's motherless daughter Isolde (Myles) is her father's property, to be married off at his will - and against hers.

Lord Marke tries to unite the English tribes behind his champion, Tristan, but, during an ambush on an invading Irish army, he is apparently killed. Tristan's inert body is pushed out to sea on a burning pyre and, happily, ends up on the Irish coast where Isolde, calling herself by her handmaid's name, finds him, nurses him back to health and they fall in love. After Tristan is forced to leave, Donnchadh decides to stage a tournament (rather like the one in 'A Knight's Tale') between all the English champions, with his daughter as the prize. Tristan wins the contest, unwittingly also winning the hand of his own true love for Lord Marke. And the stage is set for terrible dialogue, sulky acting and an inevitable betrayal.

With a running time slightly short of two hours and a love story that's not at all engaging, there's lots of time to study the rampant anachronisms in 'Tristan & Isolde' - Reynolds and Georgaris' version of history; the 16th Century poem that Isolde reads from; Lord Marke's map presentation to the English tribes - and count the number of times that people wander across the Irish sea in those pre-Ryanair times.

As Tristan, James Franco, with an ever-present pained and distracted air, is less like a thwarted lover and more like a little boy who has lost his favourite puppy. Sophia Myles is better at portraying her passion but, like Franco, she also spends too much of the film with her eyes perpetually half-filled with tears and having to wrestle with the dialogue. Isolde to Tristan on her wedding night: "I'll pretend it's you" and, later, "Why does loving you feel so wrong?" On the plus side, Rufus Sewell, who often plays one-dimensional villains ('The Legend of Zorro', 'A Knight's Tale') brings genuine gravitas and feeling to the role of Lord Marke and Bronagh Gallagher, as Isolde's maid, is a delight.

'Tristan & Isolde' is a wannabe sweeping epic, yearning to break free of its constraints, but a combination of plodding direction, bad acting and a messy script means that it never quite gets off the ground, remaining instead mired in the mud of Reynolds and Georgaris' (pseudo) reality. One to avoid.

Caroline Hennessy