Pampered pet mouse Roddy St James (Jackman) is the rodent equivalent of the sort of character that's made Hugh Grant a big Hollywood cheese.

Swanking round a posh mansion in Kensington to the strains of Billy Idol, his life is a constant round of volleyball with obliging Barbie dolls and movie matinees on the big plasma screen while his owners are away.

However, when streetwise rat Sid (Shane Richie) pops up the U-bend and despatches him into the sewers via a toilet bowl "jacuzzi" it's ta-ta to his life of luxury and hello to Thames Water's demi-monde.

Roddy finds dripping corridors and surging sluices have been colonised into a sprawling metropolis peopled by a cockernee sewer ratpack who play the machines at Geezer's Palace and sink a pint or two at the Bog & Brush.

Desperate to find his way "up top", Roddy persuades reluctant boat-rat Rita (Winslet) to help him out... but his attempts to get home are thwarted by the evil Toad (McKellen) and his hapless hench-rodents.

Despite boasting the Aardman label, this isn't a stop-motion marathon painstakingly constructed in a Victorian workshop in Bristol but a cartoon computer-generated in DreamWork's Californian studio.

That said, it still retains - without the participation of Aardman mainman Nick Park - the critical attention to detail (character, plot and dialogue) that made W&G such a compelling success story.

Jackman and Winslet ensure the characters of Roddy and Rita are as subtly rendered dramatically as their state-of-the-art animation and McKellen has plenty of fun with arch-villain Toad - "never send a rodent to do an amphibian's job".

There's barrels of invention here - electric whisks become jet-skis and Rita's boat The Jammy Dodger with its tin-bath hull, baked bean tin smokestack and submarine turbo-charger - is a model of ingenuity.

The French, in the form of Jean Reno's pack of frog assassins, get a satirical kicking - which is always pleasing - with plentiful digs at their lack of performance global conflict-wise. (The Marcel Marceau routine with a mobile video phone is priceless.)

It's a thoroughly entertaining trip below the manhole covers and a promising start to Aardman's collaboration as a computerised animator. Still can't beat W&G, though.

Tim Evans