This emotive recreation of Bloody Sunday, about the massacre of January 1972 in Northern Ireland, has predictably whipped up a storm of protest for its allegedly partisan politics and factual inaccuracies. As a piece of drama, however, it works remarkably well, bringing the chaos and carnage of that fateful day to devastating life while boasting a towering performance from James Nesbitt as real-life civil rights leader Ivan Cooper.

Based on the testimonies from both soldiers and marchers, as published in Don Mullan's book "Eyewitness Bloody Sunday", Paul Greengrass' film courts controversy from the off by declaring we are in the "City of Derry" (ie not Londonderry). Here Cooper, a middle-class Protestant and newly elected MP, has called for a march to protest against the anti-Catholic bias in the electoral, penal, and housing systems. But while he has managed to contain unruly elements on both sides of the religious divide, he has not reckoned with Major General Ford (Pigott-Smith), who has decided to use the occasion to underline the Army's control over the region.

What follows is a harrowing reconstruction of how the protest turned ugly and the Paras' heavy-handed response, which left 14 people dead, many more injured, and a city scarred forever. With the Saville Inquiry far from reaching a verdict, the chances of Greengrass, Jimmy McGovern (who has written a rival film for Channel 4), or anyone else telling the whole story are slim.

But "Bloody Sunday" goes some way towards explaining how the tragedy occurred and its enduring legacy today.