Seeing Les Misérables feels a bit like going around Westminster Abbey: the famous poster with dark-eyed Cosette gazing out through the red and blue smoke of the June Rebellion is a London landmark. It is directed by Trevor Nunn and John Caird and was originally performed by the RSC – if there are criticisms it is hard to lob them at the longest-running musical in the West End.

There's certainly no holding back in terms of drama, and protagonist Jean Valjean – who breaks his parole after nineteen years in prison and invents a new identity, pursued by his old prison guard, Javert – is impassioned from the outset. Whether you like your musicals overwrought and epic right from the start doesn't really come into it at this stage: evidently if they are going to survive over twenty-five years of ice-cream guzzling tourists they need to be made of strong stuff. Les Mis is a colossal success story and its heartfeltness is part of its enduring appeal.

That said, when the light relief does come it is very funny. As the villainous landlord Thénardier, Cameron Blakely is a fantastic comic actor – not that there is any straight acting at all in Les Mis, which is sung through. A highlight is his song, Master of the House – with its leisurely rhymes and bawdy chorus of drinkers: “Master of the house, keeper of the zoo/ Ready to relieve 'em of a sou or two”. Lyrics are by Alain Boublil and Jean-Marc Natel, and Herbert Kretzmer's English adaptation of the original French show is impressive. On the day I went, Nicky Swift was doing a great job covering as the thieving Madame Thénardier, who doesn't think too highly of her husband (though the two are clearly made for each other): “Master of the house? Isn't worth me spit!/ `Comforter, philosopher' and lifelong sh*t!” These two characters bring with them a welcome touch of lightness and irreverence amid the gloom of the Valjean/Javert saga.

In fact Les Mis is full of interesting characters – Inspector Javert, for instance, who believes people incapable of change and pursues Valjean out of an obsessive respect for the law. The web of underground characters and the entangled lives of the haves and the have-nots are ingredients of the nineteenth century novel that translate well to the stage, and avoid over-simplification: When he is first on the run, Valjean turns on the bishop who has offered him charity and steals from him instead. Rather than condemn him when the police find out, the bishop lies to save Valjean, giving him the second chance that he needs to change once and for all and become a good citizen. These are complex characters and emotions for a musical, and it is a credit to writers Claude-Michel Schönberg and Alain Boublil – and also to the English adaptors – that amongst all of the glitz of the set, big techniquey voices and the merchandise-filled West End foyer, Victor Hugo's original story is as engrossing as ever.

When I saw it, understudy Chris Holland gave an absolutely brilliant performance as Jean Valjean: natural and solid and everything the part asks for. It is usually played by Argentinian singer Gerónimo Rauch, who was a big deal when he arrived on the scene earlier this year. The show has recently undergone a bit of an overhaul, with some new faces joining the familiar ones, so now might be a good time to go and see it – certainly when I went it felt far from stale, even at the unromantic hour of the midweek matinee.

Les Miserables, at Queen's TheatreBecky Brewis reviews Les Miserables at the Queen's Theatre.4