The Home Secretary is afraid to go out at night, the economy is in free-fall and schools are being fitted with metal detectors to combat knife-crime. The world outside the Tricycle might have been expected to be reflected in Let There Be Love.

If anyone knows about the mean streets, about poverty, inequality and casual violence it is Kwame Kwei-Armah, whose multi award-winning Elmina’s Kitchen dealt unblinkingly with the savagery of black-on-black crime in Hackney. His two subsequent plays in a trilogy about Black British life have relied more on verbal fireworks, but Fix Up and Statement of Regret (currently on in the NT Cottesloe) tackled uncomfortable ideological questions, including divisions in the black community. Kwei-Armah has shown himself to be outspoken and fearless.

But what have we here? Let There Be Love is charming - even, dare one say, sentimental. It begins with what purports to be a debating point: African-Caribbean people who have been in the UK for 40-odd years may regard the new influx of immigrants from Eastern Europe with something like the animosity they and their parents experienced.

Alfred, who came from the Caribbean 45 years ago, is ailing. His two arms-length daughters arrange for Maria, a newly-arrived Polish woman, to clean for him and supervise his medication. Alfred is not pleased. But the cultural differences are only superficial top-dressing; the real subject of the play is family love.

Maria - Lydia Leonard in a delightfully spirited performance which injects just enough toughness into what could be a saccharine character - mends the family’s differences and becomes a surrogate daughter to Alfred, sharing his delight in Nat King Cole and facing his own ultimate tragedy with him. Questions about the dignity of old age and death are raised but not really explored. And Maria and the daughters are perilously close to a poor, good-hearted Cinderella and a pair of spiritually ugly sisters.

Joseph Marcell is as lovable and maddening as Alfred should be. Sharon Duncan-Brewster does what she can as daughter Gemma in a part which is underwritten compared with the other two. The winner of the Linbury Award for Stage Design, Helen Goddard, has grabbed the opportunity of her commission to provide a beautifully detailed, cluttered, shabby house for Alfred and, although Kwei-Armah’s direction is less sharp than his writing, the evening swings along on wit, music and affection.

Kwei-Armah has denied himself nothing in the heart-tugging department: terminal cancer, a lost love, reconciliation between generations, a reaquaintance with the bath-warm seas of Grenada. It should be unbearable, but I for one was only too pleased to be reminded that life-affirming writing can sometimes be as brave as the more acerbic kind.

- Heather Neill