A film about a talking bear might not seem like a major event in British cinema.

But when the bear is Paddington - a character ingrained in the nation's cultural identity - and when the film is as good as this, then it certainly becomes so.

Michael Bond wrote A Bear Called Paddington in 1958, about the well-spoken bear from "Darkest Peru" who arrives in London in search of a home. More than 20 books followed, as well as annuals, radio shows, a stage musical and the splendid 1970s television series.

A film has been a long time coming. But the wait has allowed the perfect mode of presentation to be fine-tuned, one that allows a computer-animated bear to interact with real actors. One of the most charming aspects of these stories is the matter-of-fact reaction of humans to a talking bear, and this quality is now underscored by special effects.

It opens in black and white, with a faux archive report by a droll English explorer of his expedition in Peru, as he introduces two friendly bears to the English language and marmalade. It's a wonderfully funny sequence that primes what follows.

A switch to colour brings us to the present day, where Uncle Pastuzo and Aunt Lucy live in the treetops with their nephew - whose real name is gutturally unpronounceable but will later be known as Paddington.

A natural disaster leads the young bear to London, with the promise that, just as the British war children who waited at stations for people to collect them, he will find a hearty welcome. However, when he arrives at Paddington, the reality is somewhat colder.

"Stranger danger. Some sort of bear over there. Probably selling something," declares the uptight Mr Brown (Hugh Bonneville) as his family disembarks onto the platform. Mrs Brown (Sally Hawkins) responds more warmly, offering a room for a night. But as the bear's first contribution is a spectacular destruction of their bathroom, his days at 32 Windsor Gardens seem numbered.

Making this London the intimidating place that many newcomers experience is where writer-director Paul King's adaptation comes into its own. The best children's stories deal with "difference" and the film does so beautifully, from the use of Caribbean music, signifying the real-life immigration to West London, to the battle for acceptance fought by the well-intentioned but accident-prone bear. There's a satisfying tension between open-hearted mother and son, on the one side, intolerant father and daughter on the other. The thawing of Bonneville's Brown is particularly enjoyable.

Alongside familiar characters (played by Julie Walters, Peter Capaldi and Jim Broadbent), there's a new one: Millicent, an evil taxidermist who wants to stuff her very own ursa marmalada. This malevolent obstacle to Paddington's citizenship works, just, with Nicole Kidman adding slinkiness and wit to her villain. All the actors are good value, but special praise has to be given to Ben Whishaw, whose voicing of Paddington captures the wistfulness and earnest desire to please of this innocent abroad.

The impressive production values undoubtedly owe something to producer David Heyman, who oversaw the Harry Potter films so impressively. Paul King has directed The Mighty Boosh on television, while his first film, Bunny And The Bull, seemed to be inspired by The Magic Roundabout, so he's perfectly suited to a story that appeals not just to children, but the inner child.

Often the term "family film" is used as a pejorative, referring to something children will like and their carers will be able to survive. But Paddington is the real deal.