Peterloo

(12A, 154mins)

In August of 1819, a rally for voting reform at St Peter’s Field in Manchester descended into chaos when Hussars charged the crowd with sabres drawn, killing 15 and wounding at least 500. Mike Leigh is not the first to pinpoint this event as a key moment in British social history, but his film carefully charts the build-up to the massacre from the point of view of those who took part. It sounds fascinating, and his last period drama, Mr Turner, was a triumph. This, though, is a worthy, resounding bore, full of stilted conversations, clumsy expositions, over-acting, pantomime villains and hardly a single scene that rings authentic.