If you believe the film-makers, then this is as much a part of Christmas as "hanging stockings by the fire, exchanging warm wishes and coming together with friends and family."

On the other hand, if you don't believe a word the film-makers say, then this is a cynical manipulation of a gullible public's voracious appetite for anything remotely tinselly.

After the snow settles, it's actually a bit of both - there's heartwarming whimsy to keep the curmudgeons at bay... but there's also folksy American schmaltz to stoke the sceptics' ire.

Based on the 1985 children's story by Chris Van Allsburg (no, never heard of him either), the computer generates Hanks into everything from a train conductor to Santa Claus himself.

As the gruff ticket snapper on the Polar Express, he welcomes aboard a young boy who has ceased to believe in Father Christmas... but is willing to come along for the ride.

Setting off on a trip to the North Pole, he joins a carriage-full of kids including a feisty young girl (voiced by The Matrix Reloaded's Nona Gaye) and a lonely boy yet to be touched by the season of goodwill (Michael Jeter).

The journey isn't exactly the 8. 14 from Berkhamsted - the Polar Express hurtles down gradients that make Alton Towers look like a children's swing park and skids sideways across a splintering ice lake.

(Memo to moneymen... must get Imax version showing nationally and preparations in hand for franchised theme park).

On board, there's also plenty to occupy the youngsters, including a spectral hobo riding the roof (Hanks again), who appears to have been modelled on Tom Waits.

Director Robert Zemeckis has previously worked his old pals' act with Hanks in Forrest Gump and Castaway.

Working from a source story that isn't really very strong on plot, things rely overly on computer-generated setpieces rather than any tear-duct massaging seasonal message.

The quaint subtleties of Santa's elves beavering away in a toy workshop are overblown into a vast city - imagine Detroit dedicated solely to gift production - which rather loses the human-scale charm of countless children's imaginations.

And that's really the fundamental problem. Everything is not just big... it's gross. The shame is, that goes for the sentiments too.

This is one Polar Express you might find leaving you cold.

Tim Evans