Utterly unfamiliar with the books on which Nanny McPhee is based, I had no real idea what to expect. Maybe the surprise which duly unfolded was a contributory factor, but I enjoyed it so much - and was so very aware of how much my children would enjoy it - that I spent much of its 97 minutes on the verge of tears.

The story is magical and charming, but it's the realisation of that story which provides the film's real joy. The art direction, set design and cinematography are outstanding, and the performances, especially those of the particularly vivid female characters played by the likes of Celia Imrie, Imelda Staunton and Angela Lansbury are fabulous.

I have to admit that the make-up is of such quality that I'll have to take it on trust that it actually was the remarkable Miss Lansbury under all those layers of prosthetics.

In the title role, Emma Thompson is not only brilliant, but kind of daring. She doesn't make too much of an impression - at least not a positive one - early in the film, with the result that her character grows on the audience just as she does on the children in her care.

This is a film with genuine warmth and heart, made with love and skill. It opens in cinemas from Friday, and I rather think it's a new classic of its kind.