Even a starry first night can’t guarantee a standing ovation, but on a cold, ordinary Monday evening at the beginning of January, the audience was on its feet applauding Willy Russell’s marvellous musical which has been running in the West End for over 20 years.

Maybe that was partly because former Spice Girl Melanie C has taken over the central role of Mrs Johnstone, but there’s no question that this tragic tale of twins born into poverty but separated at birth has not only stood the test of time but is still one of the most moving shows currently on offer.

Already struggling to look after a handful of kids when her husband walks out even before the latest additions arrive, Liverpudlian Mrs. J. is persuaded to part with one of the newborns by her wealthy, childless employer.

But there’s a price to pay for playing god. It’s years since I’ve seen this musical drama and although Russell’s songs – both the haunting and the jaunty – still lingered clearly in my memory, I’d forgotten the cleverness of his dialogue as an ominous narrator in a suit fills in the details of the years whilst the boys grow up in total ignorance of their mothers’ closely guarded secret.

And there’s more than enough contrasting comedy to make the heartache especially poignant.

Mel C sings with real feeling as working class Mrs Johnstone, catching the power and intensity of her conflicting maternal emotions as she copes with a difficult life and problematic offspring.

And the twins are excellent, too, as they find unexpected friendship across the class divide – one (Richard Reynard’s Eddie) immaculate, polite and surely destined for success, the other (Stephen Palfreman’s Mickey) grubby in a holey jumper, much loved but definitely from the wrong side of the tracks.

Russell has a lot to say about privilege, poverty and the cycle of deprivation.

But above all this is a very human story about love, friendship and the things that can go wrong when the truth isn’t told – and one of those shows that should be seen by everyone with a beating heart.

LOUISE KINGSLEY

Phoenix, Charing Cross Road, WC2H 0JP 08448717629, ambassadortickets.com till 31st July (£ 22.50 – £52.50)